After having cleaned the external metal parts and changed the cell I still have to glue the leather back. First I put on the rivet heads at the back some nail varnish, to avoid the formation of other "Zeiss bumps". The varnish is inert and serves as a barrier between the rivet heads and the leather. Then, some neoprene glue; I don't wait until it is dry, otherwise it would be impossible peel the leather off later on. Here it is after some black shoe polish :
The edge of the leather under the RF window is missing, it was "replaced" by some glue by the previous guy who opened it up. I don't want it to look too new (the chrome is worn off in lots of places anyway) so I did not replace this leather panel. I just cleaned it and put it back as I found it. I could perhaps paint the metal underneath black, but I don't like the idea of doctoring an antique.

And a more pretty picture, in situ :

Remember how it looked like at first :