I like those co2 pistols..look larger than they really are.
Part of the fun is finding out.
Adjusting the trigger as you have (screw OUT so it bears on the cross pin) does help a bit...keeps a little tension on the cross pins that hold the trigger parts in the housing, are a bit less likely to have a pin dribble out (but I'll still put a little square of tape over both sides...those little pins are hard to find when they do come loose).
Loading mags...another poster turned me on to this vid. It has no narration (it's not mine) and really doesn't need any. Not the way I started, but as soon a I tried it, realized how much easier this was.
Don't think they have the sales numbers here to expect much in the way of aftermarket goodies. Rectangular base of the wood stock is pretty much a uselss afectation. Human sized hands won't get any support from it, so it will eventually get reshaped. Good thing about a bit too large a stock: it's a whole lot easier to make a big one smaller than a small one bigger.
Know you were looking for the chekcered version of stock...haven't found those for sale...from what I can lear, were the same dimentions as the smooth version, so wouldn't really be any smaller.
Spares might be a problem if some major metal part breaks. Hasn't so far. As for o-rings, don't belive they use any that are unique, so replacements shouldnt be a real issue. The valve stem seal is unique (although shared with the co2 rifle and PCP rifle version), and if one of those needs replacing, think it's in the realm of home-made replacement.
Carbine stock could be done....it's a big wood grip, and reshaping it/splicing on a carbine type butt would be a lot easier than working with (partly hollow) plastic. Maybe I'll give that a try when (if) I get bored with it as a pistol.
As for changing the existing trigger...I'm not real sure what it's made out of, but doubt it will bend. The bolt and bolt handle are made from some mystery metal....it's not zinc, seems too heavy for the volume to be Al., it's not plated brass, but it's also non-magnetic. At least the trigger blade is magnetic, so I assume it's some form of steel, but I'd not really want to try heating/bending it.
Any way, hope you have as much fun with it as I have (and still am) having.