What is the correct cable end for this control and 33c cable? The hole in the control is 8mm, the pivot that most are selling has 6.35mm (1/4") shaft.

No one really dont know? no luck with this pivot. Only thing that is right is the thread.

I would just put a nylon bushing on it.

There must be right product for this, tought this is very common remote control.

I ran into the same issue years back doing the conversion. I ended up finding a bushing at the local hardware store.

About 40 years ago maybe. I have never actually seen a pic of controls that were labeled Morse.
Easily may not be able to find the exact part anymore.

I believe they are 5/16" not 8mm. The metric system didn't exist in America when those were made.
We got to the moon and back on feet and inches.... America! lol

https://www.ebay.com/itm/32510118992...3ABFBM-Iygya5g