I bought this screw assembly to accompany the Thomann Bass strap for my Russian accordion, I knew there was a chance that the screw threads were different - and they were.
No matter, fortunately the old T piece was still fine and I re-used it. I used the rest of the bits and all went fine but some spare rivets would have helped. I purchased Thoman shoulder straps too and they make the weight feel like half. Happy.