Once area that can give you trouble is engine mounting. The plane is designed for a small block .60. Compare your engine to the plans to see if you'll have to make any firewall location adjustments.
Another area of "greyness" is mounting the stab. Be sure to mark centerlines on the fuse sides at the horizontal stab location before building the fuse. In fact it may benefit you to go ahead and cut out the stab opening before building so you can compare the cut-out to the plans.

Other than those two items, PLEASE round the top of the fuse as it shows on the plans. Some people give up early and just round the edges. Looks soooo much better when it's done right.