How bad would this be? (Dessert improvisation question)

OK, dear Chowhounds, how bad would it be if I were to make a bread pudding from leftover puff pastry cups (the Pepperidge Farms 1" vol-au-vent kind)? My Dad baked up three boxes to fill as appetizers for a party, and then ended up only using about half of them. I have about 20 of the little buggers, unfilled, and a three-inch heel of old bread that's still edible, but that has become really hard and dry. Do you think I could chop these things up and make a bread pudding, or will the puff pastry go all wonky in the custard? Thank you.

PS: The photo shows the type of pastry I have. Of course, mine have already been baked, as shown on the box.