Hi Rob
As Pete says, vacuum line or fuel line can work quite well for feed roll replacement rubber. The feed rolls are usually much softer than the platen, so a person may even be able to use surgical tubing of the correct diameter. The diameter of feed roll is also not as critical at platen diameter, so as long as the rolls can rotate freely within the paper pan slots, grip the paper and release it when the paper release lever is moved, they should work. With the condition of your cork feed roll, you have nothing to lose by doing some experimenting. Hope this gives you some ideas,
Sky
We humans go through many computers in our lives, but in their lives, typewriters go through many of us.
In that way, they’re like violins, like ancestral swords. So I use mine with honor and treat them with respect.
I try to leave them in better condition than I met them. I am not their first user, nor will I be their last.
Frederic S. Durbin. (Typewriter mania and the modern writer)