Welcome to the 'Fire---from what I know about the older Weavers,
sunshades from Mueller optics will fit some of these--eg., the 3" Mueller will fit the Weaver V-16(42mm obj.) and V-24 series;
the older Weaver T-series sunshades are discontinued and are hard to find.
If any 'Fire sponsors carry these Muellers, check 'em out--if not, google Mueller dealers and take your chances on a correct fit.
Good luck!