Totally forgot to update, I've taken a week off this project, but I want it to be done within the next few days, so here I am!
The internals are basically done, I've tested it and it works nicely (will be better after some nozzle work, for now I've just ripped out the screen at the tip of the nozzle, seems to have improved range a fair bit). Today, work will commence on squeezing it into the case, which will require a fair bit more mutilation than I would like, but it must be done.
Also, recent occurances have limited my mobility (hamstring injury), so I've decided to take the lazy way out and only use parts I already have. This has led to me scrapping most of the ABS piping I wanted to use in the reservoir, now I'll be using an old X-Stream Super Cobra's reservoir (holds about 1.3L) but extended with some ABS.
Here's a piccy of the internals:
That long hose is necessary, but it will get in the way so much.
Also, if you're wondering what I've done with the check valve that I lopped off the HC...
It's gone into fixing a broken MD6K, which I plan on changing in a huge way. It's also getting the HC's old PC.