I have this exact same problem.
I have a few Orig 68/69 Cables, yet the Spring Ring Clamp ends or the #10 feeders are damaged. When I reached out to Lectic Limited for inquiry they WILL NOT service any original components due to Liability and any negative effect to sales of their restoration line products.
Now if you GM Orig Factory Cable that just has a damaged Round Ring Spade terminal you can source replacements via Digi-Key or Newark electronics, sizing the Barrel to the proper gage and the Ring hole to the proper size for the stud on the solenoid. Crimp, Solder, Insulate.
A lot of cars judged are not negatively affected by using Factory Fit style replacements ? I think ?