Chuck,
Thing to do is buid it as you want to build it, from whatever is in the box. Take the instructions (usually required by the rules in most box-stock classes), but also ... take the box.
To really nail it down, take an un-opened Jawbreaker kit along ... if you have one. Any argument with the judges would be quickly dispelled by cracking open a mint, sealed kit.
Speaking from the experience of years of 'head-judging' that would do it for me!
Good luck! Nice model.