pequeajim:

I didn't use the servo trays either but did use the covers.
I made a thin ply floor for the aileron and flap servo pockets and glued them in with Elmers. I then mounted each servo with the thin black rubber servo tape. I use this method often and have never had one come loose.
I had to inlarge the servo lead hole in the wing with a dowl but still had to remove the plug from the lead in order to get it through to the root rib. There is a ply rib in the wing about 2" from the flap servo pocket.
As for the elevator, I mounted mine with the gap on the bottom, the way is should have been done but now
the heads of the screws show, no biggie.
I also heated and bent the tail wheel too the rear half way between the axel and the coil spring. It looks much better and the coil now works. Oh, and take your time trimmin that damn whindshield.