John,
If you intend on starting in Basic then how scale doesn't matter... you can fly anything, like a PT-40 Trainer.
For Sportsman through Unlimited the aircraft must be easily recognizable as a full scale aerobatic aircraft that has performed in full scale aerobatic competions. No 3-views are required, unless you have a rather obscure aerobatic aircraft that not too many people know abot nor do you have to use a scale colour scheme.
If it looks like a Raven then it will be alowed to fly. There is no static judging componnent to our contest, although your aircraft may be admired by your fellow pilots!