I'm having a big problem finding sun roof parts (or replacement sunroof assembly)

I've looked at EBay, Craigslist, Kijii, etc...
I have researched the original company that manufactured and installed them (ASC - still in business but no longer have information on parts)

I have looked for similar (70's era) cars that have power sunroofs (VW, Mopar, etc) and I get close but at the end of the day, it's either a manual sunroof car or it's already sold.

Several of the internal parts, tracks, aluminum guides, etc.. are either missing or corroded too bad to reuse and I'd prefer to take out the entire power sunroof assembly if possible.

The only other option that I can think of is to replace it with a modern sunroof assembly.

I'm open to ideas or suggestions....

Thanks in advance
Mike