somone 11.....I move the trailing edge of the fin and stab a 1/2 inch to shorten them. I doubled the rudder and add a inch to the elevator. When i mounted it i put the stab in the stock place and just butted the fin againt the back of the fuse. Thats why the fin looks like it sits behind the stab.

I didnt see anything about the spruce spars but yes my kit had them. I changed mine to 1/4 x 1/8 spruce and doubled it up in the first 3 ribs. Plus i made my own ribs. Yes sounds like a lot of work but two or three of the ribs i cut wieght as much as one of the kit ribs. Saved a ton of wieght in the wing.

Or you could use some real lite balsa for the spars and glue some carbon to it. Light and strong.

I thought about replacing the ply fuse with balsa but it was to hard to find 48" 1/8 balsa.

OK...Hope this helps.