...and thanks for all the comments and interesting info Gareth.
Some brief chrono results using a R2A - 10 shots with each make of pellet.....
RWS Hobby
Average velocity 617 fps
Average energy 10 ft.lbs
RWS Superdome
Average velocity 568 fps
Average energy 10.39 ft.lbs
Milbro Caledonian
Average velocity 568 fps
Average energy 10.14 ft.lbs
H&N FTT
Average velocity 557 fps
Average energy 10.11 ft.lbs
Looking at those results, it looks like the power is down from what one should expect.
Inside, we can see that it looks drier than a Nuns Nasty with bits of fluff and durge http://imgur.com/a/P4I4C
From photos of the outside http://imgur.com/a/LJXxq
Buttpad with cracking to the side and hardly any wear on the bottom http://imgur.com/a/27POS
I'll leave things as they are at the moment and when I have some spare time, I'll strip it down and relube it. Hopefully that will bring up the power levels a bit more