I'm working on a Robotron inspired Mame cab and painted the sides without pre-made stencils. I painted the mini-cab graphics instead of the full size art, but you could use the same technique.
As Frostillicus said, since the graphics are mostly straight lines, you can just mask them out and spray the correct color. Home Depot sells a straight edge low stick white masking tape that worked very good. It left very crisp edges. The 2084 can be done the same way.
I used airbrush frisket film to mask out the circle and the W.
It turned out nice, but it took alot of thought and time. I had to draw out all the graphics, trace it onto the cab, mask out all the blue sections, spray, and then do the same with the red.
If you can trace a copy of the original graphics from your cab, using the HD tape should give you good results if you have the time.
Here is a good site with the Robotron paint codes and he has a stenciling tutorial using a different technique than tape that turned out nice on a Stargate cab..
http://www.tutankham.com