After flying my Senior for a few years built fully stock I used the cat jumping on the rear tailplane as an excuse to rip mine apart and do a rebuild. Mods I did were:

1. Taildragger. I switched to a dural aluminum blank (believe it was a 60 sized) mounted just aft of the wing leading edge, using 1/4" ply to reinforce the bottom, tri-stock to reinforce the ply and some extra 1/4" balsa to fill in and reinforce the fuse sides for mounting the tri stock to. For the tail gear I went straight below the rudder to make the linkage as simple as possible.

2. Bolt on Wing. Again added 1/4" balsa to reinforce the fuse in the canopy area. Used a pretty basic setup with dowls holding the front into a builtup area on top of the windshield area, and wingbolts going into hardwood blocks in the rear. I also fully sheeted the wing center section area top and bottom, using ply in the back and filled in the area the wings bolt through with balsa. It worked very nicely and although the builtup area on top of the windshield area was a bit taller than the stock balsa it blended nicely.

3. Ailerons/Flaps. I just ripped the wing right behind the rear spar,adding 1/4" balsa behind the spars, and 5/16th balsa shaped appropriately for the leading edge of the control surfaces. Servos were in the center area, and activated the control surfaces with pushrods. I also cut the wing in half to remove half the dihedral and made new ply dihedral braces. One thing I didn't do that I should have was install access hatches for the bellcranks as sure enough I needed to make some mods after it was all finished up and ended up having to go through my covering.

4. Doped finish using Koverall. The Kadet certainly had no problem with the extra weight and it looked so much nicer than plastic film. Tougher too. I landed in the corn once (deadstick) and there was absolutely no damage to the covering anywhere.

I also switched the engine shortly after that time from a K&B 45 Sportster to a Saito 65. The mods didn't really change the Kadets flying too much. Everything worked and was strong enough and it still flew much the same (SLOW) , however it would roll better than with rudder only. Mixing in rudder with the turns really tended to make it look quite scale in flying. The flaps were neat, and would really make it baloon if you dropped them with full throttle which was fun to do if you were the ribbon plane at a funfly.

Here's the kicker though. I ended rebuilding a stock Seniorita after a friend got me a broken one from a garage sale and eventually sold the modified Senior. The stock Seniorita is powered by an OS40 FS Surpass and is the perfect plane for buddycording a newbie to, and for sunset flights. The modified Senior is 18 years old now, and still is still flying regularly with the fellow who bought it.