I've adjusted the fit by using coarse-grade (F?) pumice as my lapping
compound. Might save you a step.

If it's too loose, use the pumice to body some shellac on the mortise.

"Owen Lowe" wrote in message
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After the whole thing rests for a couple hours I lap the lid to the
base. Making up my own homaid lapping compound as such: I skillfully
shape and build an aluminum foil tray. Then using two small sections of
wet/dry 320 sand paper, I rub the grit faces together over the tray so
that it catches the dust. Then mix in some furniture wax to make a small
amount of slurry and spread a bit on the tenon and mortise. Working the
lid on and off and twisting it in complete revolutions will, after a few
minutes, yield a perfectly fit lid.