Hi to all!!!

I recently picked up a Cermark/Topgun composite spit never assembled. After reviewing the build threads it seams to be extremely weak where the retract rails are mounted (numerous posts about guys ripping retracts out and having to rebuild)

Ive been building off and on for 35 years, balsa mostly, then standard covering or fiberglass then paint. I’ve never worked with composite materials. So my question is if I peel back the bottom of the wing to rebuild the landing gear rails and beef them up what do I need to do to patch her back up? Can I use my standard method of balsa sheet, then fiberglass mat and resin? Thanks in advance!