This pulley has no manufacturers stamp. The example found in the 1965 Recreational Equipment Inc. catalog is also free of any markings and matches in all other measurements listed. The pulley has a 3/8 inch hex head axel bolt instead of the slotted round head bolt shown in the catalog.
The nylon pulley wheel is very small and space for the haul rope is limited by the bend in the side plates. I tried setting up the pulley with period correct Plymouth Goldline rope and it was much too thick to function efficiently. There are 1970s vintage nylon kernmantle in our archives that would be too thick for this pulley as well. The photos above show a 1/4 weight laid rope.