This hull is gone I think. I had a discussion about that last year with a dealer. More than three inches was a problem in his opinion. There is a guy on the Spark forum who replaced his hull by himself and it was very complicated. And Spark hulls can be unscrewed, not these GTIs. Must be feasible but only a dealer will be able to tell. These polytec hulls are more common now.
I have swapped a PolyTec hull on a Spark 2 UP, not an overly complicated job.....A little time consuming and you need to pay attention to details but certainly do-able.....this machine however looks like it is past the point of repair.....the hull is gone and part of the top deck is broken.....by the time you get all the parts, etc....and the hours involved with swapping everything over......probably a losing proposition.....INSURANCE claim assuming it is insured......otherwise, part it out perhaps.