Great Britain, copper alloy Admiral Vernon medal, 1739, Vernon / Porto Bello, ex-Adams. AC-PBv30AA. 19.34 grams; 39 mm. Lustrous UNC in light brass color with some high points slightly flat (Adams: "weakly struck but no wear"), it's color probably due to higher tin content than most. XRF: 40.75% copper, 51.58% zinc, 5.48% lead, 1.14% tin. Pedigreed to the John Adams Collection (with his handwritten tag).
Estimate: 400 - 600 USD