There is a pretty good set of files on line, I forget if it is CGtrader or the like. I got the files just to see and they do look pretty accurate. The only other source is a guy (Steve) on the RPF who sells casts of each side that I know of.Is there a current source for the Cheyenne Flight Helmet Greeblies?
Or search the web for the model kits. Alienslegacy forum has a comprehensive list of the kits and parts needed.