Thanks for all the replies. I've been reading them as they come in. Lots of good ideas.
I started out try to mask with some vinyl electrician's tape. But it must not have been sticky enough, as the edges lifted up here and there. So I peeled it off I went back to blue tape. I cut the blue tape with a straightedge and sharp knife to get a good straight line. Burnished it down as best as possible with my fingers. At least it did a better job of staying put than the vinyl tape did.
All I really needed to do was to spray RED, so I had to mask off over existing white. I had to mask off 3 raised body lines, approximately 1/16" wide and the full length of the shell. The raised body lines also have molded-in rivets the full length of the shell. I would imagine a masking challenge even for the pros.
I tried spraying some very light coats of white to seal the tape edges. I had thought about doing clear as a sealer coat, but didn't want a compatibility problem, as the clear was one brand, and the white and red were another. At any rate, probably didn't get enough white down, however. Then I went to the red, and tried spraying very light coats, allowing several minutes between them to tack up. Maybe I should have allowed more drying time?
Like I originally said, I should be able to touch it up easy enough, and if it isn't 100% perfect, I think it will be good enough to satisfy me (and I'm still kinda' picky about such things, so you know it ain't that bad). Actually, if I stumble across another FB-1 in the future, I'll most likely buy it and try my luck again. Maybe I can get perfect results the first time around? If I follow everyone's tips, my chances should be tremendously improved!
Don't anyone hesitate to add any more good ideas, either. I'll keep watching.