I think the props for 1966-1968 J&E 100's are the same but before you spend your money, get verification. Here's a link to BRP's website which still has listings for 1968 models:
Additionally, Michigan Wheel lists three props for 1967-77 Model 14 Large Gearcase OMC I/O's which I think are also compatible if the diameter and pitch work for you. Again, try to get verification before purchasing. You should be able to find them through the iboats.com online store.