The watch should not gain a minute overnight. The movement probably needs a service and an adjustment.
The dial has been re-painted, as the inking on the logo seems much too thick. With Hamilton collectors, redone dials are not as big of a deal as they are with Swiss brands.
Here is an original 1951 catalog entry for the Secometer B:
View attachment 840194
Note the distinctive seconds hand with a pointer. I can’t tell if your watch has that or not.
If you bought this at a good price, it is certainly worth investing in the necessary service.
Wear in good health,
gatorcpa
Click to expand...