Grumpy The Mule wrote:
Well that's sad. I doubt it's nylon which was invented in 1938,
maybe phenolic? Wood filled phenolic which swells... ugh!
Maybe you can rinse it with solvent then dry it out so it will
shrink back to nominal dimensions. The rest of it is constructed
of isolantite and brass which solvents won't hurt.

Could be phenolic but it really seems like a plastic of sorts. Hard to
tell. The front bushing is where it got tight and there's no easy way
to get it out for a thorough cleaning.

-Bill