The two successful fuse's I molded were for my old Sierra design, a Trivial Pursuit based ship, and I did a left and right shell. Slicing the front to achieve the taper I had in it worked very well, and with the formers shaped from sectioning the mold buck for patterns, the fit was quite good.
When installing controls I worked with the outboard half on the formers and then added the inboard side when they were complete. It worked out well that way, and with a 3/32" sheet fuse, was fairly light.
The ship flew very well, suffered an inverted splat from a dust devil, and I built the next fuse the same way, reused the wing and tailfeathers, and had a very good ship again. Wish I had saved the mold buck, but it got lost in the shuffle! I have a Bob Hunt foam wing ready to do a third one.