I'd strongly recommend against putting anything like that back in an oven. Sculpy puts off some pretty toxic fumes. Most folk don't notice because they've got good oven ventilation--or do small items.
I learned this the hard/stupid way doing batches of larger sculps, in an ancient apartment with terrible ventilation. Long story short: roommate and I had to evacuate the apartment, throw all the windows open and walk it off outside for an hour in the middle of winter. I made us both terribly sick, had to call poison control. It was a mess.
I'd hate to think what kind of combined fumes would be created from Sculpy and Krylon.