There are many different watches in the Hamilton Converta series.

The first two photos below show a Converta III with stainless steel case and 14K gold bezel.  It is rather unusual in that it houses a Hamilton cal. 502 movement — this movement is half way between the cal. 500 and 505 — it was never officially released.

Below, the one on the left is a Converta IV while the one on the right is probably a Converta case but someone has customized the dial — the giveaway is the rather poor luming of the hour markers and poor lettering — you will not find this dial in René Rondeau’s book “Watch of The Future”!