Got a note from a friend (not on the list) that Dometic pointed him a
fellow in Indiana as the Dometic technical guru for older refrigerator
models (i.e. the ones on our Westy's).
He is:

Dave Griner
All Season's R.V.
Elkhart Indiana
1-800-344-0673

He is supposed to be able to get hard-to-find parts that the local service
centers can't.

I have no experience with Griner.   Just a pointer to a possible source.

Dave