I am looking for the definition of a profile model as applies to profile stunt events. The AMA definition is a bit vague.
"The" definition depends on where you live, because (in the US at least) the profile events are all local.
This was all flogged to death recently in the rules section, as Kieth mentioned.
http://stunthanger.com/smf/index.php?topic=28905.0. Lots-o-comments.
I'm not going to take the time to look, but I thought the AMA definition was more spare than vague: the engine needs to be exposed from lugs to plug (well, "crank centerline to head", but that doesn't rhyme), and the fuselage behind the trailing edge needs to be no more than 3/4 of an inch thick. I take that to mean that beyond those restrictions, anything goes. If you need more, write it into the rules for your local event.