I had the boat inspected and the hull is dry. There is evidence of a hull repair, but it's hard to say what happened, the work looks professional. The outer hull looks good other than many major dings that I'll be filling with epoxy. The smoking gun is in the forward compartment. On the 2520 you have a rectangular hatch on either side, but on my starboard there is a round hatch that has been installed in front of the rectangular one. It has a removable dry bag installed in it, but when you remove the bag you can see that blown-in foam has been removed, and the area has been repainted. There's some good glasswork in there that I can't distinguish from factory work without seeing the other side, but the paint doesn't match the paint on the remaining foam. She passed the hammer test, and is in good shape, but it should have been barrier coated after the repair and it wasn't.
(I'll post some pictures later if anyone is interested).