I had a 1502/11 in my spares and tried, not sure of the age of the bracelet. I have not found any answers what was the correct one for the Ranchero's. Seen them on differrent bracelets, BOR and flat link. Normally i prefer it on leather strap.
"SeamasterCosmic 2000" are different i both case and shape that the "Seamaster Cosmic" I guess You are thinking on the normal Cosmic that is 34-35 mm. This ref. is 38 mm. ex crown. and I think is the smallest of the Seamaster Cosmic 2000.
Not all watchmakers like these cases with their inner and outer case and "press in" front and back in gaskets. I have had these two as project watches, non running, well used with patina for some time. Found a watchmaker that would fix them and now they are brought back to life again. He asked if he