Thanks so much for the ideas -- you guys are the best! Actually my husband suggested cutting off the hard edges, and since I happened to have an adjustable cake ring (gadget fiend that I am), I used it to trim a layer to 8", since that would remove the crust around the edges. After I did that, it looked like the inside was still pretty moist. So I took a gamble and threw together a simple vanilla bean buttercream and frosted it and flew out the door with it. The friend I took it to will give me the straight dope re: whether it was up to my usual standards. We'll see.
So now I have three layers' worth of delicious crusty cake edges, and I could freeze them, or make a trifle now. Time to get out that trifle dish I rarely use (eclectic serving dish fiend that I am)
Thanks again.
Emilie