I don't fancy my chances modding one of those triggers to fit, if I'm honest.
Anyway though, I have some news.
I fitted an M150 VSR spring just now, unfortunately my chrono is being a bellend so I've no idea what the hell the fps is, but using .43s, the stock hop parts + a biro ink tube nub, stock barrel, stock trigger components, an ASPUK piston and spring guide, I was able to hit a metal drain pipe at approx 80m, measured with Google maps. Most other shots came within about 1.5m to it as well, from what I could see. Though I'm by no means experienced when it comes to judging the flight path of BBs at that range, my back drop was the sky so I could see the black BBs, so it's quite hard to gauge at what point along their flight they were deviating.
I have almost no faith that the stock spring guide stopper will hold up much longer though, it was visibly bent before I even fitted the M150 spring, so I dread to think what it looks like now.
The rest of the trigger parts seemed to perform fine, I've not looked at them yet either, but I have confidence they'll still be fit for hard use.
On the down side of things, my range dropped off substantially after about 60 shots, and although I've not looked into it yet, I suspect the hop rubber is going to be in tatters.
Also, I bought a VSR10 metal hop arm from ASPUK, the B type one and it's massive. A good cm too long to fit in, as well as being too fat and too high as well. Just far too chunky in every dimension to fit into the gun.
I might give R-hop another go and buy a spring guide stopper that fits. I have a PDI one but it won't go in because the arm you pull it out with hits on the gun chassis when closing it, so you can't get the gun together.
Once those parts are sorted though, I actually think it could be made a rather decent gun, everything seems to be holding up really well and I'm astounded I hit 80m with mostly stock parts and without the accuracy being too terrible either.
In fact I was so surprised with the performance that I'm starting to worry I might be firing massively over the 500fps marker, 'cos if I can get 80m from the stock rubber and barrel with this spring fitted, an R-hop ought to put me well into the 100m zone, the shots seem to carry a ridiculous amount of momentum as well, I could see this covering more than 150m if I angled the barrel.
Actually properly excited about getting it up and running effectively, 'cos it's going to be a beast. I'm still having feeding issues though... Pain in the posterior to say the least.