This is a duplication of sorts of the removable servo tray that was engineered by my Father in my original Vertigo II. Due to a nose heavy condition on this build, I have all four fuselage servos (Rudder, Elevator, Throttle & Retract) all in one tray, and set as far aft as possible. The mounting rails are spruce, and are glued and glassed to the inside of the fuselage using polyester resin. The Spring-Air retract valve mounts in the middle of the tray between the retract and elevator servos. The tray started out as a hatch from an R/C sailboat that I built 20 years ago (I still have it). I laminated it to a piece of 1/16 ply (grain cross-ways) and then milled out some excess material to lighten it up a bit. The existing cross braces keep it stiff across the rails. Re-use of existing materials helps keep the cost down, and adds a unique cool factor to the project.
Now I have to engineer a cool way to mount the battery pack as far back as possible.