I did a fair amount of searching, but nothing conclusive seems to pop up. I'm wondering if anyone has recommendations for a metal bracelet (preferably BOR!), but for fixed lugs.

 

You could use this on fixed lugs.

 

... That looks very interesting; what is it?

 

Basically a flattened spring with tabs to hook on the sprinbars or fixed lugs. Retailed for about $1.95 in 1942 worth about the same now. This one was on my uncles watch when he was killed in France 1944. The watch came home he didn't.