Are you referring to the Contessa 35, the folding model with the f 2.8 Tessar? It is a lovely camera! Have a look at Camera Quest:
https://www.cameraquest.com/contessa.htm
You might have a look at Mark Hansen:
http://www.zeissikonrolleirepair.com/index.html Here's a link to repairing the light meter on the Contessa 35, but be aware that Mike repairs Contax II shutters!
http://elekm.net/zeiss-ikon/repair/meter-repair/ Not a task for the neophyte, although the procedure for reviving the meter on the Contessa is simple enough that I might attempt it.
I have a Contessa 35. Lovely machine! But not for fast work, rather for contemplative shooting. Note that the lens has filter threads on the OUTSIDE, not on the inside as is common. Tim at filterfind.net found a series adapter for me, and also a nice little leather case for the adapter, a lens shade, and a few filters. Tim is a good man.
Gotta find a Jaguar XK 120 to go with my Contessa 35.....