I traced a water leak in the AC to rainwater coming through a series of fine cracks in the "step-on" side deck (terminology?). I started cutting in the center of a slightly soft area and then moved aft and forward until all evidence of moisture penetration was gone. The deck appears to be cored with about an inch of end grain balsa. See attached pic of exploration in process. I've since squared the edges and cleaned out all the wet balsa. While the cavity dries out, I'd sure like some advice on the next steps. I think I need to re-bed a new core with thickened epoxy and then lay up a series of cloth laminae, allowing each one to harden until flush with the rest of the deck ... right? Also, do I need to go out and find balsa or will something else do, e.g., pine plank or plywood?