it really doesn't matter about the bows in the banana boat top longerons or the orientation of the firewall in relation to the longerons as your alignments should be established on a longtitudinal plane in relationship to your angle of incidence of your airfoil profile and all your alignments ( horizontal stabilizer, and thrust line) will be established on that longtitudinal line. Do yourself a favour and purchase a lazer level, it will make your life so much simpler.
