Hi Kerry - Yeah, I'm well aware of this issue. It's too bad. If you only sell paper plans it's probably safer, but people are pretty unscrupulous. I had a company making unique chopper parts for a while and had several people directly rip off my designs. That was such a drag.
Just for fun, I modeled a nose and grill shell for a hot hod just now:
I don't have a lot of experience with lofting shapes like this, so it took some screwing around to get to a shape I liked, then I got carried away and made a grill for it.
Then I exported just the nose itself as a STL solid (not a thin shell with an opening for the grill like the rendering). I copied it to my mac and used "slicer for Fusion360" to generate a buck, then exported full scale plans.
I could see that working to get to a starting point, assuming you had a decent CAD model to start with. Kinkos can print 36" drawings on a roll printer. Or I guess you could have the stations laser cut.
Anyway, enough screwing around.