Ian all the advice i can give you is take as long as possible on teh final shaping of the hull peice`s, as you`ve noticed there isn`t much room for error.
all i can suggest is the chef method, try it,taste it. leave a good 4 mm of flash on the moulding after cutting most of it off, and take it down with gentle filing and sanding, but continoulsy checking the outcome on the model. the more time and effort spent here will pay dividends in the final model. once youve done teh first one, tape it on the hull and this will give you a guide for the adjacent peices.
apart from that
