Yes, if you can't source a genuine part, you can use a piece cut from a suitable rubber hose. I did it, it took a few tries to get one I was happy with, but it is do-able.
I seem to remember an earlier post by Charlieny on this topic. I needed a seal at the time, followed his advice with a piece to rubber tubing, and it worked like a charm. Can't recall the timing of the post, but it was a couple of years ago.
It steadies the mechanism. Light drag is better than no contact. It isn't like a modern setup with return springs. there are springs but it requires the slight drag to keep it all settled.
The Ford TSB says to clean, lube and turn three turns inward. Then drive the car and turn screw outward until slight spark knock is audible under load , turn inward until you experience no knock under slight load......
And a helmet would be the same issue.........