I've had it to pieces now, sorted the immediate issues out (bolt coming loose and feeding mech essentially breaking), took some photos of the piston and trigger mech and stuff, so I'll get those up at some point. Hopefully people will be able to tell me which parts will be compatible etc. after having seen the current parts.
Yeah but it's from JDAirsoft, and from what I've heard about them, I might as well use my warranty as toilet paper.
Besides, I'd have had the same issues with the next gun as well if I got a replacement, it's far better to just learn to solve any issues you're having, than to just give it the shop to sort out.
As I said, it's all sorted now anyway. Know the gun inside out, only parts I've not taken apart yet are the trigger mech and the rear...