Water damage from old leak

Over my rear window (emergency exit) the seam (covered by a  2 " tape the same pattern as the paneling ) has some warping and "rippling" of the tape and panel.  It's a little soft (not too much) and I'm debating whether to open it up an clean it up. Some questions ...

The inside of the pod is plywood under the wall paper. I have never taken it off but I would want to stabilize the the plywood so it did not get any softer. a penetrating epoxy sealer would be the way I would go you can even get syringes to inject the sealant into the wood. I use west system marine epoxy but there are products designed for stabilizing soft wood one of them is call Liquid wood.  They are expensive hard to find and if you have a small job you can't buy it in small enough batches.I get mine from a paint shop here is town but a local hardware store had a package with a small amount of the resin and hardener in it for small jobs.