In the OP's case, I would say that he got two things to fit together, by grinding and filing, that weren't meant to fit together, which is why infinity is off. The pieces that I have (previously posted photo) do all fit together quite well, and the mount adapters are different depths so there is infinity focus with the same lens on different mounts. However, I'm not clear as to if what I have are called T-mounts, or something else.