Ways to fix warped superstructure?

The usual way is to heat the plastic by warm water and then hold it in position until it cools.

I have used the hot/cold water method for bendy barrels on tanks a few times & hotter than tap hot, I use the microwave to heat the water hotter than out of the tap but not boiling & then ice water after straightening as needed....it works with some care exercised when heating the plastic, barrels are thinner I reckon than superstructures but still plastic.

Use caution & give it a try. Good Luck.