Now be very very careful leaving in the sun, pieces can distort if it's too hot. Really depends on how flexible the fiberglass still is, I've had two different lots from Jim and one was a lot softer than the other, had a bicep which started out round distort oval, managed to save with wrapping tape around and leaving.
With the putty as it does contain acetone it may very well have reacted with the primer, or the primer may still have been a little soft, or was too hot