For that old of a truck, I would contact Hust Bros Auto Parts, in Marysville, CA. I have seen three of them in their warehouse. There phone # 530-743-1561 ext 1 ask for Ted. They have warehouses with a lot of NOS.
I had a Cleveland company rebuild mine for 100 bucks and it works great. Added to cables after the fire...LOL....and so far so good.
Best to just get rebuilt and not deal with a maybe working starter.......sorry......it is in and done.