Well,
here's my PGP.
I always wanted one of these so I picked one up from eBay. Notice it's the ol' school model with the aluminum pump handle. When I got it, it needed a lot of cleaning. I replaced the bolt o-ring with a spare o-ring I yanked off of a Trracer bolt. Currently, it needs the pink seal replaced, since everytime the 12 gram is punctured there isn't a good seal. I may just pick up an entire valve assembly to completely restore it.
So here's some upgrades I'm considering: