EC 12 History shows a number of manufacturers and boats with a waterline length of 42 1/2 plus or minus 1/2 and only a beam limitation of 11.5 inches, location not specified, and more that one actual hull shape. That was limited in 1978 to boats "conforming" to the TREASURE TOOLING mold and measurements. Still more manufacturers were allowed and some modifications made(keel width primarily) , followed by the "95 STANDARD" hull and then finally the 2004? Class molds. This made the boat closer to a one design mold, but there is still a lot of leeway for boat beams in building.
At a NCR about 2004, a spread sheet was made of all boats at the NCR listing various details and weights. I cannot locate that now.
What it showed was there was a wide spread in boat weights.
When Tom Germer was following up on Rick Wests proposal to use a weight standard about 2012 he was trying to figure out how to arrive at an all inclusive weight range that would accomodate all class boats. A herculean task.
NOW it might be possible to arrive at a weight range for boats out of the 'class molds', (wider keels) AND grandfather all older boats to the waterline measurement. It would take a motion to change the class rules approved by the class in AMYA election. Based on history, (I go back to 1973) I would still advocate against it, and am not sure it would eliminate your concern.
We have had Class measurement certificates to make it easier to administer Championship Regattas. Eliminating the need to measure at an event. If a skipper wishes to protest a boat thought to be violating the measurement rules, he should do so.
http://www.ec12.org/Admin/Files/EC12_Measurement_Policy.pdf(We have had a tank available at NCRs held at St Augustine.) We had one at Peachtree City, Oak Hollow, cannot recall the others.
AS a Measurer, have you found anyone attempting to cheat?