[Source] Box catch

Hi from here in the steamin’ South,

I’m in the process of fabricating a watchband and would like to use
a box catch for it, so can anyone recommend where I can buy one
(some) in sterling? Eventually I’ll figure out how the heck to make
one myself, but it would sure be nice to have one already made to
study. Any suggestions? An Internet search was a bust.

As always, thank you soooo much in advance, Carol Carter-Wientjes