need answers for a convertible s-10

i have a 2001 s-10 that i purchased for fairly cheap which i was happy about but the only thing is that it is a convertible, the previous owner cut about 6" from the windshield,from side to side and flush with the bed so there is no roof what so ever.and no upper half of the door my question is how do i cover the 2" gap that is there from the headliner to the sheet metal, you can see the foam that is there from the factory, i dont know if i should use fiberglass and if i do how should i prep it or if i should weld sheet metal and do all the steps and paint that?????? in a hard bind here somebody please help me out.