I'm about to replace the roof on the '76 FJ55 I'm in the process of restoring. I'm curious about where to cut the old one off and weld the new one back on. I'd also like to know about the use of gas when I weld these together as well. I have access to a MIG welder which has the capability to use gas. Neither roof has been removed from the truck yet. The good roof is on a VERY rusty midwest truck while the bad roof is on an otherwise solid California truck.