No leads here or wrong forum but I will do a multi-belt order to V-M in Tape recorder belts, shows a good selection.
https://www.thevoiceofmusic.com/cata..._rec_belts.asp
I think the days of using part numbers from schematics and specialty universal-fit parts makers is over.
The main motivation is RCA-Hitachi video equipment for Dave A., who has entrusted me with a repair. A belt, 100% sure will fix everything.