Bezel insert maintenence/preservation

[jban5]

This recently came into my life and after doing a little standard cleaning off of the debris of the past 48 years I like what I see.

There is a little encrustation of some sort that I wonder about and if I just stop it from getting worse that would be ok.

I would like this to stay pretty much the same which makes me ask what the collective wisdom is on protecting the insert. Does anyone have any good or bad experiences with things like waxes? I wonder if the solvents that are likely in most would possibly have a damaging effect. Perhaps Renaissance Wax?

Or, is just cleaning and leaving alone best?

Any help is appreciated