Unglide cassettes that I've seen are screwed together, easy to disassemble and re-configure. I don't know what the lowest tooth count sprocket is for Uniglide, but Hyperglide sprockets are easy to adapt by filing the narrow gap to the UG width.
Your best bet is to look for non-Dura Ace UG and HG cassettes on Ebay, with 11T or 12T small sprocket, then mix and match.