PCP long term storage

So....just joined this forum (already posted a bit of a rant about Huggett.... sorry). I feel very privileged to be here with so many who know so much more about PCPs than I and I am looking forward to learning from you all. One quick question (and I apologise if this has been done to death already). What is the best way to long term store a PCP? I have built up quite a collection of them and some do not get fired from year to year...but I cannot bear to be parted from them...that may be a familiar emotion/illness for many readers here? On paper it all seems quite simple, but then I get them out to decide which to move on and discover each one is VERY SPECIAL and cannot be sold. Yes, I have been infected with some sort of wonderful disease! So, if I can't sell them what is the best way to store them? Should I lube O rings etc? e.g. have an old MGBGT, in the winter I deflate tires, put battery on trickle charge etc.......... what is the best drill with PCPs? Discharge air VS keep it pressurised and so on?
 
Just wipe down the exposed steel parts that are prone to rust (but not aluminum) with an oil-based rag (e.g. silicone, WD-40, Ballistol, etc.). It is best to store PCPs with air in them as doing so allows the O-rings to remain expanded and keep sealing the air. If you live in a humid region and plan to store your rifles in a padded case, it might be best to place a desiccant to filter out the moisture that will be trapped in the case (even though the rifles have been wiped down with oil). These should be all you need to do.