Hi Tim.
I'd be interested to know what club you're at that's encouraging WB's to join the racing.... maybe I could get in a visit.
I used to race my dogeared GP14 against more whizzy boats under PY club racing (and even win sometimes !) But win or not I always told them I got the best deal as, while they were sitting in the clubhouse waiting for me to finish, I was getting more sailing in than them.
Sadly I can't help you with anything official about WB handicap. Best I could think of to improve mine would be to find a quicker boiling kettle.

Ken