Yea,

integrating the vertical into the fuse sides is a good way to go if building from the original plans. The only issue is that the grain of the sides wants to run lengthwise while the grain on the vertical wants to run parallel to the LE & TE. I would mate two pieces of 3/32" sheeting with the rear piece having grain parallel to the rudder hinge line and the front piece parallel to the fin LE. These would then be glued to the top of the sides flush with the outsides. There will be a little bit of a step at the fin sheeting junction as the 3/32" is thinner than the sides which could be made from 3/16". If you used 1/4" per plans, you will just have a little bit more material to produce the canopy indent along the datum line. A triangular piece of 3/32" or 1/8" sheeting could then be installed at the base of the fin atop the fuse sides bridging the space between the fin sheeting. Bonding a full length hinge post between the fuse sides at the tail is also a good idea for proper alignment. Span the full length of the fin including the sub fin under the fuse.

The main thing that bothered me while framing up a wood fuse with the original plans was that the sides continue sloping down in the stab area. This causes a bit of a problem later when you come to insert the stab as you end up having to cut away part of the fin base. It also makes it hard to level the stab (particularly because it has pronounced anhedral) because you don't have a level surface (datum) from which to measure. For these reasons, and because the continuous slope to the sides is unnecessary, I leveled the sides where the fin starts. This accomplished three things: 1) it provides a level datum from which to measure stab alignment, 2) allows the fin to be easily framed up separately and then dropped on to the fuse easily which has a balsa floor in this area and, 3) provides more material all around the stab insertion point and allows one to add balsa doublers (needed with thin sides for scaled down versions) in the area.

With my plans one could in principle even use thin 1/8" fuse sides and add a 3/8" x 1/8" or 3/16" thick stringer centered on the datum line on the inside of the fuse - this to provide material and permit the tuck to be produced. The two formers in the tail boom provide more than ample strength and also allow the top deck to be sheeted with 3/32" avoiding the thick sides, top block and tristock. I'm fairly confident that it could result in a model with an overall weight of one pound less.

I have some pictures of how I framed up a vertical (fin & rudder) a little differently. I'd be happy to post them but don't want to do so before you post pics of your build and/or if they are of no consequence. If you would like me to post them, just let me know. Leo posted a beautiful shot of a glass T720 fuse which I thought might serve as "carving" inspiration.

David