Just wanted to check...I just took apart some P1 suspension I bought. When I pushed on the damper I was able to compress it slowly, should I be able to compress it?

 

Of course you should! But the V5 struts normally paired with the P1's are fairly high gas pressure so pushing down should be difficult (if you are a puny guy like myself!). If you can push down on them easily then they have outgassed and you will be looking at picking up a new set. Technically they are rebuildable but I don't know anyone in the UK offering that service.