I'm thinking of doing this for something to do, I know it will work (sort of) but without be able to set dwell times for the solenoid it'll probably be a disaster. The idea is to do away with the Fabco MSV-2 and replace it with a micro switch with a lever. Screw the rod to the lever mimicking the MSV-2 and bolt into the same position. Then, wire a 9 volt battery with a resistor to the micro switch and then onto a Spyder solenoid as they're dirt cheap. Plumb in a QEV and an mpa-3 and see what happens!

This is what I think will happen.
1. It will work fine.
2. It will work fine until I start rapid firing at which point it will probably short stroke as there is no way to control the time of the solenoid turning on or off, (Dwell) as it it will be on until you release the trigger. A tiny timed relay would probably sort the short stroking out if there is such a thing. This is the smallest relay I've found so far.

http://www.semitek.cz/tyco/rele/agastat/md0.pdf

That said it might work better than a Pneumag.

Any thoughts?