Top Tips from Paul.

I always wrap my pistols before storage in their foam cases.
Oil and foam can discolour finishes.
Also stand the cases up rather than lay flat to avoid pressure rashes.

Having done all of the things suggested here be aware that there are many exceptions to the rules.

I have bought Umarex pistols that have been badly stored with co2 in ,and neglected but they look and shoot fine.
I’ve bought Gallery Queens and new ones that shoot poorly or have other defects.

Annoying!