Hi Allen,
It is not clear where you got the replacement seal from, but if it does not look right, it probably is not.
However, it is possible that during the last 50 years, the oil seal has worn a miniscal groove in the shaft, and that a thinner seal could run on an undamaged section of the shaft.
I would also like to point out that those seals are available with double lips. They are therefor wider and obviously have two sealing lips.
So, if you cant find a seal as wide as the original, consider a 'double lips' seal, which would have a similar width as the original, plus the advantage of two sealing lips, possibly running on undamaged surfaces.
Regards
Chris