Both had diagonal span wise wrinkling of the skin and a straight edge placed along the after hat section showed both stabs had a permanent (albeit small) bend. Both stabs were deemed not worth repairing and were replaced. I should note that this occurred when spins were still required for the Canadian PPL. In one of the cases the pilot had told a friend that the airspeed was at least 10 knots over the redline and he pulled hard enough to grey out. The second is more ambiguous and the link between the damage and a botched spin recovery is not as clear. Contrary to their reputation, C 15O/152 will accelerate quite quickly at very steep nose down attitudes. A good example of this is the split S maneuver. Entered from 85 kts and level flight a 4.5 to 5 Gee pull is required to keep the airspeed in check. Any less and you will be right up against or over the redline
As you had pointed out the "aerobat" models of the C150/152 have most of their beefing up in the tail. I can see why....