How to "clean" plastic part of a Copal 703 case?

[Nikos B]

Hello,

Any pointers how to clean the plastic case of a Copal 703? It has some patina and I know that is not removable but I would like to clean edges that have dust or other smudges without causing any discoloration.

Any suggestions on what to use ? Warm water?

[Johan de Jong]

Warm water and soap is safe and removes most of the dirt.
See also this post for other things to use and, more important, what NOT to use: https://www.flipclockfans.com/forum/...ck-restoration