Is this for s PW conversion ?
If so do you know the mfr. of the conversion?
I would look very carefully at the motor housing ( Inside & out), as well as the mounting plate edges, sides etc. for ANY markings, numbers etc. Over the years I've had to play investigator more times than I can remember when a customer bought a car at auction with no paperwork.
However, I did once work for a company that would buy 1000- 5,000 electrically controlled valves at a time. The owner would then hire a temp worker from (Manpower, oops I just dated myself LOL) and have them sit at a table and dremel off all the markings. His thought process was to force customers to come back and buy the valves at an outrageous mark up (40 or 50X ) if I remember correctly (bas--rd).

If nothing is found you could get lucky by Googling '19xx vehicle power window kit" and repeat the same with "conversion" in place of kit. I have found information by pulling up old postings, magazine articles etc.

Next IMO would be to start looking for a substitute that can be adapted over.