Ok, Arne, if I had to true up those curves with only a belt sander, I would mark pencil slash marks all along the curved work area to confirm where wood is being removed while sanding. The next step would be to install a fresh sanding belt, probably an 80 grit, then get on my hands and knees on the teardrop floor. Holding the sander over the edge, and while looking down at the fresh pencil marks, I would make light passes all along the edge. Then checking the results with a square, I would again mark the high spots, make more light passes, check w/square again and so on. This takes a little time but can be done if sanding is not too aggressive. A light weight sander works best for this kind of job, and the key is to let it float like a butterfly and sting like a bee......tenderly.
More info will be posted when I get all my ducks in a row and can organize the sander information in the correct order. Hang tight.
Roly, retired So Calif woodworker, remodeling my house, finishing the "Stacker", doin' the mister-Mom stuff and when time is available, working on compiling "Beltsander-101"
