It's definitely off of an older Subaru. It doesn't have the dust shield the same?? Have you tried to fit it onto the EJ tranny and the SVX Hub?? If it fits and you want to know where to get another, I'd post in the "Old School" section of
USMB the folks over there are experts on the older soobs.
You may also want to contact
MWE Axles. They specialize in rebuilding Subaru Axles and I'm sure they can help you find something that will work, possibally even custom building something????
Good luck and keep us informed, this seems like a neat project.