There was a good thread a few years ago detailing USAF Model 15's.
My memory isnt what it used to be but IIRC the USAF 15-2 (&-3?) 's were pulled from existing (made for civilian consumption) inventory then had the USAF mark applied.

I'm not certain but my foggy memory is they had a wide TT/TH with Magna stocks,
Also seem to recall an article saying that Uncle Sam seemed it fit to dump large amounts of them into the ocean .

IIRC Lee knows alot on this topic.