In the early days (50's/60's) of SLR lenses by independent lens makers there were several versions of the T-mount type mount. I have several that don't fit any T-mount lens I've owned. Finding what you need may take a while.
Thanks for the help. I figured it might be something like that. Hard telling where I might find an adapter. It would probably be easier to just buy an old Petri if I wanted to use it.