I've stripped mine down in readiness for the obligatory mods and it was plain sailing until I came to the pivot pin for the side lever. The 2mm Allen key wouldn't touch it and started to round off the corners so I used a Torx driver (T-9?) instead which did the trick. Also, the rear plate was a right pig to prise free as it seemed overly snug in the breech block, but it did eventually come free without any damage. The barrel was absolutely filthy as in jeffsky's video, as was the hammer and spring assembly, but it's all cleaned up nicely. From previous posters experience with a .22 I'll try a 2.5 TP with a 1.6mm spring and start with the reg at half a turn in and see what's what. I'd sooner start low and increase the output rather than the other way round.
Just need the postie to deliver the bits and bobs now and it'll be happy testing days.