John,
I think that the contest is more of a flight schedule practice, there is no static scoring, and there is no builder of the model (BOM) rule, so it sounds low key, fly what you brought.
More than likely the CD will be more than happy to see another competitor show up and fly. Call him and see for sure.
Download the FAI rules off of the AMA site and see the differences between FAI and AMA, and then you will have a notion of what the flying rules will be before you get there.
Have fun,
Chris...