Hi! Sadly, my My CP88 which has only had about 200 pellets through it (I was overtaken by serious illness) sat too long with a CO2 capsule in place (naughty!). Now it will not hold pressure at all - cartridges just immediately vent. I've already tried the dodges of putting oil on the seal, warming it etc but no joy. I've been quoted £70+ for a local gunshop to do this, which makes it uneconomic (as this is probably about 50%-75% of its second-hand value)

I've bought some of the new (red/orange) seals from Chambers and have seen the exploded diagram (!) and also found some helpful info and pictures from this site of a partial stripdown for lubrication etc, but can't find anything that goes as far as I need for replacing the seal. Has anyone done this and have any pictures/ advice (I know - don't do it!) please? (BTW is £70+ the going rate for this repair, parts supplied, or is that the going rate?)

Thanks for reading, and in advance for any help. Cheers!