Base silver coin of Tostão D. Sebastião I (1557-1578), with countermark of 120 Reis of D. João IV (Portugal - Law of 3 February 1642), and countermark crowned 200 Réis D. Afonso VI 1656-1667 (Brazilian Law of 22 March 1663, Regiment of 7 July 1663). This type of silver Tostão coin from the 2nd dynasty were controversial coins with an irregular monetary standard in Brazil, as it was a coin that in that colony was circulated at the same time in different places for different values. The stamps of 150 réis and 200 réis were applied to old coins of Tostão according to the value they had in the respective regions, not always complying with the legislation in force (Alvará 6/7/1663 and Regulation of 7/7/1663), taking into account Considering the multiplicity of countermarks  that appear applied to this type of pennies and given the size of the colony and the different places where coins were stamped at the time, some different stamps may have been improvised and applied unofficially in order to avoid the devaluation of the currency.

Portugal silver coin with countermarked of 100 Réis (type III) of D. Afonso VI 1656-1667 Law of March 22, 1663, on, 4 Vinténs Mint Porto of D. João IV 1640-1656, obverse inside pearly circle crown flanked by dots and dot under the mark "LXXX", Legend "D.G.REX.PORTVGALIE.ET.AL", on the reverse inside a pearly circle the Cross cornered by "P", Legend IN.HOC.SIGNO.VINCES", World Coins Portugal KM#426.3 Scarce variant with and without stamp

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Coin with 250 Réis countermark (rare “2S0” countermark, smaller size, variant type “G”) of King Afonso VI (1656–1667), applied on a Half Cruzado silver coin from Porto mint, of King João IV (1640–1656) — A. Gomes J4.91.11. The legend reads “...REX PORTVGALIE...” with smaller PPPP letters. Reference: World Coins Portugal KM#434.3. There are numerous unclassified and still-studied variants; however, this is the only coin I know of with this specific combination of typological and countermark variants, making it, in my opinion, an example of great rarity.

Coin countermarked with 500 Réis from the reign of King Afonso VI (1656–1667), in accordance with the Law of March 22, 1663, in the Kingdom of Portugal, and with the Royal Decree of July 6, 1663, and the Regulation of July 7, 1663, in the Kingdom of Brazil. This countermark is struck over a silver Cruzado coin from the reign of King João IV (1640–1656). There are several known variants of these countermarks; this example corresponds to the variant bearing the letter “S” instead of the numeral “5,” forming “S00” (World Coins Portugal KM#437). King Afonso VI (1656–1683), known by the epithet “The Victorious,” was the twenty-third King of Portugal. He was born in 1643 and reigned from 1656 until his death in 1683. His wife was Dona Maria Francisca Luísa Isabel d’Aumale and of Savoy. During his reign, coins were minted in copper, silver, and gold, and some of the most emblematic Portuguese coins were issued. However, in this reign only a single coin type was struck in copper, with all remaining issues being in silver and gold.

Portugal, silver coin with 500 Réis Countermark (S00, variant type "E") of King Afonso VI (1656–1683), struck over a silver Cruzado from the Évora Mint during the reign of King João IV (1640–1656) – World Coins Portugal KM#437.2. Coin likely recovered from a shipwreck, as indicated by the presence of saltwater corrosion. King Afonso VI, known as "The Victorious", was the 23rd King of Portugal, born in 1643, and reigned from 1656 until his death in 1683. He was married to Maria Francisca Luísa Isabel of Aumale and Savoy.

coin copper of X Réis 1753 D. José I, Brazil Former Portuguese Colony, World Coins Brazil KM#174.1

Silver 640 Réis (2 Patacas) coin dated 1771, struck in .916 fine silver for circulation in colonial Brazil during the reign of King José I, known as “The Reformer”, the twenty‑sixth King of Portugal. Born in 1714, he ruled from 1750 to 1777, a period marked by major administrative and economic reforms led by the Marquis of Pombal. He was married to Queen Mariana Victoria of Bourbon.

This specimen belongs to the “SUBQ” variant, distinguished by the unusual placement of the dot above the letter “Q”, a feature considered scarce among the known sub‑variants of this issue. The obverse displays the crowned royal coat of arms, while the reverse features the armillary sphere over the Cross of the Order of Christ, following catalog references KM#193.2 and Gomes 53.02. The coin measures 37 mm in diameter and weighs 17.92 g, within the expected parameters for this colonial emission.

Brasil, Silver coin of 150 Réis 1754 of D. José I (Portugal), Shield countermark of 1809, legend error, "ATAN NGIS". Coin of 150 Réis 1754 Silver D. José I (Brazil) Series J, "R". Rio Janeiro, with "Shield" countermark of D. João Príncipe Regente (1809),  error variant in the legend "ATAN NGIS"

Brasil, rare silver coin of 80 Réis 1816 D. João Príncipe Regente of Portugal, 4 vinténs silver 1816 "R" Rio, World Coins Brasil KM#305. Rare coin, being a coin that rarely appears on the market and in this state of conservation is very very rare. D. João Prince Regent (1799-1816), was born in lisbon on May 13, 1767, son of D. Maria I and D. Pedro III. Due to the Queen Mother's illness, Prince D. João took on the responsibility of government from 10 February 1792, assuming it definitively as Prince Regent from 15 July 1799, until his mother's death.

Silver 960 réis coin, known as the Patacão, issued in 1810 for colonial Brazil under Prince Regent D. João. Struck at the Rio de Janeiro Mint (“R”), this VF+ example shows characteristics typical of overstruck pieces and is valued for its historical relevance and importance within Luso‑Brazilian numismatics.

Coin from Brazil (former Portuguese colony), featuring the "Escudete" countermark of Prince Regent D. João on a 1774 XX Réis copper coin of D. José I (Brazil), as catalogued in World Coins Brazil KM 175.1. This example has a High Crown with a Potent Cross featuring a filled design similar to a Cross Pattée. Legislation: Royal Charter of April 18, 1809. Following the French invasion of Portugal and the subsequent transfer of the Portuguese court to Brazil, the Prince Regent ordered, as a means to cover expenses and due to the scarcity of circulating currency, that earlier Brazilian coins from previous reigns be countermarked with the "Escudete" on both copper and silver coins. For copper coins, this countermark doubled their face value, effectively increasing their legal tender value twofold.

Brazil, silver 640 réis coin dated 1784, from the joint reign of Queen Maria I and King Peter III, minted in Lisbon. This is a silver two-pataca coin, “High Crown” variety, listed in the World Coins Brazil catalog under number KM#207.2. The coin was issued during the reign of Queen Maria I for circulation in the then colony of Brazil. Maria I and Peter III (1777–1786) ruled jointly; Queen Maria I, known as “The Pious,” was the twenty-seventh monarch of Portugal. Born in 1734, she reigned from 1777 until her death in 1816 and was married to King Peter III.

Portugal, silver coin with edge reeding and Orla Nova die of King Pedro II, established by the law of June 14, 1698, applied over a silver Half Cruzado of João IV (1640–1656), bearing the 250 réis countermark (2S0, type “A” variant) of Afonso VI (1656–1667), within the historical context of Portugal and Brazil. This is an unclassified legend variant, absent from both the Alberto Gomes catalogue and the Brazil Bentes Catalogue. The piece features the Orla Nova edge and die of Pedro II (1698) over a silver Half Cruzado of João IV, displaying a type (b) border legend on the obverse: ✤IOANNES.IIII.DEI.GRATIA.PORTVG.ET.ALG.REX.

Portugal, silver coin with rim cord and Orla Nova (New Border) die of King Pedro II, according to the law of June 14, 1688, applied over a Half Cruzado silver coin of King João IV (1640–1656), bearing the 250 Réis crowned countermark (variant type “B”) of King Afonso VI (1656–1667), Portugal and Brazil.

Rim cord and Orla Nova die of King Pedro II (1688) over a Half Cruzado silver coin of King João IV (1640–1656), with border “b” or type II. On the obverse, legend variant No. 1 ✤IOANNES.IIII.D.G.PORTVG.ET.ALG.REX, and on the reverse, legend variant No. 2 ⠂✤⠂IN✤HOC✤SIGNO✤VINCES.

There are many variants not yet classified in the Alberto Gomes catalog; numerous combinations of legends and border types exist, some of considerable rarity, even though they are generally listed in catalogs in a generic way. In my view, this coin represents a combination of some rarity.