Every 6 months or so, on a nice sunny day, like today in Canberra, I take my beloved AstroPhysics 152EDF F7.5 Starfire (Oil spaced FPL53 triplet...with 4" field flattener
) out of storage and give it several hours of indirect sunlight, just to prevent mould. It is stored in a dry environment in our light filled warm city apartment, but I like to make sure. I remove all caps from the OTA and finder scope, lay it on the bed pointing out the window but not so the sun could shine in directly of course. So far, after several years of using this approach, the objective looks excellent and clean
There are some tiny chips around the dust cap edge of the (removable) dew/dust shield, just from putting the cap on and off and because it is stored standing with the objective end down, otherwise it is is pristine condition.
What a scope, haven't used it for a few years now, so can't wait to eventually get it setup under the pristine dark skies up at Eagleview
Setup in the field for imaging
Mike