we had the same trouble many years ago in adelaide with 14"skiffs. originally there were 4 at henley SC and two at Brighton and Seacliff YC. they chose to sail all together but at a different club each week. it worked for them, as they got some very high profile sailors building boats to join them. guys like Robin Duessen, Grant Geddes- who went on to win several national and world titles in I14's. they also ran once a year an invitational day, where they selected prospective sailors, these dont have to be big names, just people showing some interest in the class, and they ran a series of short sprint races swapping boats each race. if you scout around your clubs for younger sailors who might be looking to step up into a senior class i.e. mozzie. these dont have to be cat sailors either, the 14's chose a mix of dinghy, cat, fixed keel yacht, windsurfer etc. even people walking on the beach who stop for a chat while your rigging. a presentation and a bbq afterwards to show off the social side of the mozzies also go a long way.
it might be worth a go, or even a discussion??