Hasselblad V mount to Canon EOS adapters are very common...plenty of choices. I looked earlier today for Hasselblad screw-fit to Hassy V...no luck finding that. I thought if there were a Hassy thread to Hassy bayonet adapter, that two adapters could be used, and everything would be cool. As in Hassy thread-to-Hassy-bayonet, then Hassy bayonet to Canon EF. I'm not exactly sure when Hasselblad abandoned their original mount, but I thought it was like 1948 after the 1600F was ended that they went to the "modern" Hassy mount. And prior to the 1950's, Hasselblad cameras were pretty niche-market...nowhere NEAR the popularity of Leica thread mount, so the demand for an old-style Hasselblad adapter is going to be very,very small.