Finding parts to replace original 50+ year old parts is getting harder and harder to do. Original parts are getting harder to source and quality replacements tend to be pricey. Either way, your in for some time to search these parts out. There are several vendors who may be able to supply you with with a new old stock (NOS) yolk.
I have used Speedi Sleeves which is a thin stainless steel sleeve which will renew the wear area for your new seal. When you have a groove worn in the yolk you will need to use Locite 660 compound to fill in the groove which will prevent the thin sleeve from forming down into the groove from the pressure applied by the seal. I have used this system years ago and the yolk is still in service today. If you can't source a NOS yolk, this will keep an original correctly fitting part in service.
The parts you will need to repair your original yolk:
National 99156 Speedi Sleeve (Other venders make them but the part number tend to be the same) Size 1.559 - 1.565
Locite 660 Compound
Below is a link to the Locite 660 so you know what you need to be looking for if you choose this route.
https://www.henkel-adhesives.com/us/en/ ... e_660.html
Harold W.
MVPA #6833
1945 GPW
1950 CJV-35/U
1951 M38 1952 M38
1962 USMC Contract M38A1
1953 Strick M100 1967 Johnson M416
1968 CJ5 4-Speed 1969 CJ5 V6