Nigel,
Talking to Kevan Bloor (Alverbanks) yesterday about such things, what really matters is whether the sail shape is ok, not whether the settings correspond to those proscribed. Seeing as you have a set of Alverbanks sails, it might be worthwhile talking to him. There's also a recent link on mast step position. It's currently on side 2 of the forum under "How much heel?"
Cheers!
Jim.
Nigel - I bought N3339 (same boat as yours, Ledger built but has carbon rig) from John Murrell and he set it all up. Seems you have a local 'guru' to help you out. I'll try to bring a tape measure next time I'm out. However - different sails make a difference - at weekend was using P&B main and felt slower upwind (seem to be getting some backwinding at front of main) - last night sailed with a 'flatter' main (Hyde) and same jib and was flying!
Kean