yes ,..looks like they were intended for the horizontal tail surfaces ,..I've actually seen a few different aircraft of model 3's and 4's that had flying surfaces on horizontal tail areas only ,..none on the vertical,..
I can tell you the 2 fly's well with flat surfaces ,..your cruise will be around 75 mph depend on prop and pitch settings,..
the airfoil surface has less drag so you might gain a couple mph in cruise
,..the difference will be how close you keep your gaps closed,..the laminated air will seperate more from the elevator leading edge area the larger the gap creating like a buble of disturbed air at the hinge point between the horizontal stab and the elevator,..this same effect will be on the vertical surface and rudder as well.

Chase