My Kaslo SD50F that I got pre-assembled had problems with the truck swing. You probably won't get the shell apart cleanly, but I chose to remove some of the material from the trucks where it hit the steps and it's pretty much unnoticeable and they don't hit now. You could also try to remove some material from the shell, but the shell is harder to replace than the truck sideframes. If debonder is acetone, I would avoid it on a plastic or resin model.