From what I have seen of the high end competitions, top gun, NATS, super scale heli, they all state they want a "published" 3-view of the aircraft. The easiest place to get this is the pilots manual or in many cases the little plastic models do have a 'published' 3-view. Having been a judge in scale events, (helicopters only of course), the 3-view is to make sure that empennages are correctly located, correct proportions, ect. They are not used for the detail stuff. That is where your documentation and pictures come into play. Essentially, if you are using a plastic model you are making a scale model of a scale model that may not be correct, and as I judge I would not accept such documentation. I have no seen the statement in the rules about the plastic model being ok for a 3 view.

Concentrate on the details you have good picutres of. If you can make the detail look like the picture you will get good marks. If it isn't documented in pictures, and all fancy and stuff, from the judges standpoint, too bad, nice part, but no proof, so it isn't "judged'.

Regardless, a three view is not that hard to get, even from stuff way out of production. Even coffee table books have 3 views. Just look.
Jack