The RB2 Airsporter is sort of easier to take apart because the rear trigger block doesn't screw off/on but just has 3 bolts (2 either side and one through the Maxigrip rail) and then it just comes out, the RB2 also has a small alloy plate that is fixed in place with a grub screw that is sandwiched between the rear underside of the cylinder and the trigger block cocking arm mounting section and it stops the cocking slide from coming out of the rear of the cylinder, I think the rest of the strip is the same as the older Airsporters after that.
Pete