I have two Mamiya M645 Super bodies, and one M645 Pro body. I received the proper strap when I bought my first M645 Super. I am amazed how hard it is to locate another strap.
The lugs on the older (pre M645 Super) bodies are different than the lugs on the M645 Super, M645 Pro, or M645 ProTL (or at least one of them is).
In addition, the lugs on the left side are different than the lugs on the right side of the Super/Pro/ProTL bodies.
It is just about impossible to figure out how to order the right lugs for your camera, unless you can deal with Mamiya USA, and they aren't keen on dealing with us Canadians The catalog pages that I have seen from the Canadian distributor or Mamiya USA just don't make it clear how to tell the difference between straps for the older M645s, and the newer Super/Pro/ProTL bodies .
Apparently, there is an Optech (sp?) starp that can be made to work with the Super/Pro/ProTL bodies, but Optech's website says otherwise.
If anyone out there has a set of lugs that will fit my Super or Pro bodies and would like to sell them, I'm interested!