The whole table that the griddle sits on, including the casters needs to be replaced. Their terminology is "shelf". The whole thing is collapsing. I'm sure it could be reinforced with bolts and such, but it would be easier to just get a replacement and slid the griddle onto it and be done.
It is in a tight place and would have to be moved by professional weight lifters. Its a 60 inch wide grill...heavy.