Needed a 3 inch reel for an old Panasonic RQ-114 (1963 era) that I am restoring. Didn't want to feed ebay so I designed one from scratch in Fusion 360. Works just as well as the original. Just glue the two together. Don't really know if anyone else needs one, but here you go...
Included a .step file of the design if you need to tweak it a little.
The author hasn't provided the model origin yet.