Thank you both for your answers. I've been researching for a long time, and I have learned of the reason for locking out reverse. I'm happy that I learned that part by reading, not from experience. I was thinking of making a bushing. I think that I would be able to get one in place by removing only the side cover. Before I started messing with it, which will not be soon, I wanted to ask people who do know what these look like. Besides the instruction that I reference above, I have a copy of the BW repair instruction and a copy of Ford's version. I will look more closely at those to see if I find reference to a bushing. I have also an OD transmission from a 1955 Chevrolet car that I can take apart to look at.
1950 GMC 100 Panel Truck, 1958 270,
3-spd Saginaw with BW OD,
3.73 12 Bolt Differential from a 1966 C10,
Front Disc Brakes
Bought it in pieces 9-1976, driving since 6-1978
Follow in the DITY