Cluster Housing Refurb

I'll have to go to the book to verify those readings. My memory sux.
The thing is... that build up on the winding restricts the movement of the bi-metal. And where its breaking and falling off there's a lot of it. Even if the windings are intact and not shorted to the beam, it can't move the needle like its supposed to. I wouldn't be surprised if you found the black pepper evidence in the oil gauge and maybe the temp gauge too.
Some have suggested the nasty carbon build up and the oil like staining all comes from cigar/cigarette smoke. Its a reasonable theory.