Well the pump is a Sterling the UK's best effort at a pump marker, possibly the STP top end version. One of the finest pumps ever made. Looks really clean with little use and quite popular right now with the pump revival we are currently seeing.
The other is an Automag by Airgun Design of the USA set up with Co2 expansion chamber to run off remote bottle worn next to your pots on your backpack, remote line runs onto gas through stock. Marker also seems to have the carbon fibre grip frame which was a ( pricy ) aftermarket addition plus the splash anno barrel.
Its a Sterling Silver I would say, one down from the STP. The STP had a far nicer grip.
And the automag is a late one. The GFN frame was a down-spec on later models, not an upgrade.
The pump on the "silver" is stock.
I did bought a STP with same pump years ago.
I don't remember why there is two (the round one which is like a cocker pump, and this one which go around the barrel).