Hi Tim, Gary, don`t take it too seriously, remember if other class sailors are rumouring that the Mozzie has a favourable rating, what they are in principle doing is promoting the Mozzie as a boat that is faster than everybody thinks, you have a great situation in that sailors from other classes are doing your marketing for you !!
Take it one step further : Keep posting results to VYC to get more accurate ratings for all classes, and get sailors from other classes to petition VYC to lower the Mozzie handicap. Once you have it in writing from other classes that the Mozzie is "unfairly fast", your class should see some positive growth .
Stephen, have to agree, OD or Formula is a better way to test skill than open class, but looking at the Forster regatta results there seems to be a varied group of one-or two boat classes that need to be given an open class to race in. I think the Mozzie rating is probably quite fair looking at the comparison with an ISAF rating the Mozzie would acchieve, but I think the YVC rating for Tornado and F18 have been unrealistically lowered by the consistently high level of sailing in these fleets as you say, which makes it hard to beat a well-sailed Mozzie on a Tornado or F18,given the ratings. (just my opinion). This is where performance based ratings fall on their heads - they assume equal skill level across all classes.

So if you think the ratings are wrong, slow down a bit at the next few regattas