[Boatanchors] Siezed bakelite

[Revcom Electronics]

Boatanchorites....

Surely someone has done this before so thought I would ask.
These don't have tubes, but used with tube sets.

I have a set of "antique"? Goldak headphones, Type 45, 
where one earpiece has the cup ring frozen on due to rust
I suppose.  Other side is OK, need to open it up to see if
can repair coil and clean diaphragm.

Tried penetrating oil, no luck, any suggestions to loosen 
it up other than bust it to smithereens?

Rod
K0EQH