Watch List notes:

Postumus, Romano-Gallic Emperor, 260-269. Antoninianus (Silver, 22 mm, 3.17 g, 12 h), brockage mint error, Cologne, 260-261. Incuse of reverse. Rev. P M TR P COS II P P Mars standing front, head to left, holding globe in his right hand and spear with his left. Cf. AGK (corr.) 60, Cunetio 2387, Elmer 129 and RIC 54. Very fine.