As I dig through the mounds of wreckage and leftovers from my RC career so far, I have started to try to use up some of it on experimental projects. This is my latest frankenplane, so far I have the body from a PZ Trojan, the wing from a GeeBee Senior Sporster from Hobby Lobby, and the leftover canopy I didn't use on a Great planes Easy Sport. I think the effect is something like a P-47 mated with an FW 190.....

The issue I'm struggling with is the horizontal stab. What is in the pics is a leftover stab from a GWS Formosa. Its a bit smaller, in length and chord, than the original stab from the Trojan, but the elevator has more surface area. But overall it seems too small. I went around to some of my other planes, and did some measurements of wing length/ Stab length, and then started to mock up a stab out of depron based on that, but it seems too big. (last pic)
Can anyone tell me if one of these stabs might work, or if not, what else might work?
So far, the plane is:
Wingspan = 48"
Length(firewall to rudder hinge) = 30" (w/cowl and rudder = 34")
Formosa Stab = 15 1/2"
Homemade stab = 19"

Im not a math wiz really, but is there a simple formula for determining Stab size from wing size? I had also thought of making the Fuse a little longer, but that would be a last resort. With the way the fuse tapers it would be hard to make it seamless, besides keeping the tail straight.