Hi John,
If I were to do the work on the stabs I would not interfere with the integrity of the skins. I would Dremel out the root of the tailplane and then rebuild using plywood blocks. I did this on my FB Hawk as my previous SM one had a tailplane failure.
Sad as I was quite enjoying this model and considering another JL model, the SU27. I am sure you were enjoying your model too.