I got a pair of Tannoy System 12 some time ago who had been used the way they should, as a portable monitor. As you can that had led to lots a bumps and scratches.
I, along with Des just picked up some T12's, PA monitors, smaller ply cab than your System 12, but already they sound great. Can't wait to re-house them.
Have you made any modifications to the crossover? Could you post some driver pics please?