good point on the truer the cut the less lapping there is to do. Some times i will try to regrind a face just to make lapping easier, however it can also make it worse and with all things in life that require any skill, practice always helps. I am finding little things that help all the time, but can be so long winded to try to point out one little thing. Renting tools can be a big help. If you can go down and rent a 10" wet saw and see how it runs. Often you can get weekend deals, and the price is an easier payment than purchasing.