Paul,
The overarching rule covers it:
"The only aircraft allowed is the PDQ Flying Clown or faithful replica."
The way to comply with this rule is to: get a set of plans made up to document this design; or, buy a kit that is generally been accepted as a reproduction of sufficient accuracy to comply. This is not an event where you get to design from scratch, and so the rules are not set up to tell you how to build a compliant racer without the plans or a compliant kit.
To wit, no PDQ Clowns had wing-mounted gear, retracts, flaps, metal pans, engine cowlings, etc. Rather than spell out every possible permutation, and end up with an encyclopedia of rules, just follow the overarching rule. And, if lawyering instead of actual racing is the goal, then remember rule number 9:
"Other Notes: The event director may disqualify any entrant who is not in keeping with the spirit or intent of this racing event."
Race. Have fun. Don't be the Smokin' Eunuch.....
Dave