Thank you all for your responses. I have figured it out, thanks to the article that Scott (MusicCity) linked. I did something similar. I had read where U.S. stripes were 15"...in 1/48 scale my stripes should be 5/16" wide (I errantly made those on my P-51 3/8"...off by 1/16", oh well). I established the inner border of the white stripe, then used 3/8" wide strips laid side-by-side, establishing the outer border. All that area was sprayed white, then I again used strips to define where the black stripes would go.
Aw, h-e-l-l, I'm rambling. When my wife gets back from vacation (she's got the digital camera) I'll post pics...turned out GREAT!
On Bench: AM P-51B, Tamiya 1/48 F4U-1A
On Deck: Hasegawa F-14's (too many); Tamiya P-47D; Academy P-47N;