[Bushwacker]

Reglassing the top of the stringers will certainly help, but once you install the deck/cockpit sole and bond it to the top of your reglassed stringers, that'll tie all the stringers together, creating a BIG increase in torsional stiffness! I think Potter used a polyester cabosil/putty for that, but if you use epoxy putty, it'll cost a little more but will have much higher bond strength. That will definitely eliminate the racking you have now with no deck in there!