www.925-1000.com

Update:

I used a microscope to look at the Swan mark and it looks like there is a letter 'D ' in the top right above swan's tail.

Also, the watch case has two covers on he back (the movement cover and the decorated cover). Both covers have the the swan and the initials marks.

I have a silver watch case with an oval mark containing initials STR inside. There is another mark (it's the blur on the left side of the pic) which looks like it is the swan hallmark for French imported goods or small guarantee. The case is a pocket watch case converted to a wrist watch. Contained ...