Since you have access to a machine shop and if you have the skills, why not just make a VA that instead of having an LPC under the barrel, a threaded ASA so you can just screw the bottle directly into it? Basically horizontally as opposed to the regular vert orientation. Either Tippmann or PMI had a marker in the late 80's or early 90's that was set up exactly in this manner. I looked but couldn't find any pics of it -
I made a very rough drawing of what I just mentioned
http://www.spyder.tv/forums/attachme...1&d=1298527147