Well, the "one with the big head & the horses" is based on the design of a Syracuse tetradrachm. Head of the nymph Arethusa surrounded by dolphins on one side, chariot & four horses on the other because the tyrant of Syracuse won the Olympic chariot race but was denied a medal (so he went home & commemorated the event on his own coinage).
If it's "bigger than a silver dollar but doesn't weigh as much", I wouldn't tend to think it genuine, as the original should be about quarter-sized (although thicker) & made of silver.
The other has the design of a Byzantine piece, but again, ancient coins (aside from a very few, enormously rare exceptions) rarely exceed 3 cm in diameter.
If it's "bigger than a silver dollar but doesn't weigh as much", I wouldn't tend to think it genuine, as the original should be about quarter-sized (although thicker) & made of silver.
The other has the design of a Byzantine piece, but again, ancient coins (aside from a very few, enormously rare exceptions) rarely exceed 3 cm in diameter.






















