This weekend I had the 5 floorboard sheetmetal pieces welded in to repair rust holes. Also the driver's side floor pan frame rail was straightened as it had been used by a floor jack. Unremoved rust makes the mig welder spit sparks. First I drew on the floor with a marks a lot around the holes using straight lines to make the cutting and fitting of the new pieces easier. After I cut along the straight lines using an angle grinder I made cardboard templates from the floor holes. I bought a piece of sheet steel 16 gauge from Thrifty hardware and put the templates on that and drew on the metal to outline the new replacement pieces. I used an angle grinder to cut them out but I had to use a bench grinder to adjust the shape of the 5 repair pieces to fit properly. Some would have overlapped the metal which would have been easier but I didn't want an area to trap moisture. 16 gauge is slightly thicker than the 17 gauge originally on the car.
Coincidentally the gentleman who did the welding used to own a scarab 71 240Z. He put nitrous on his and I don't know if that is typical for scarabs but he said he had trouble with the rear shocks coming up through the floor and he had to weld reinforcement in to prevent that.