How did you do it?

I would need to see some pictures of what you have but you can overlap them like you describe and plug weld them and seam seal it. I've used sheet metal screws to get the panel where I want it then weld and pull the screws and weld those closed. There is pneumatic tool that will punch holes for plugs and offset flange. I've used that too to get the metal down in locations where you need to touch a frame rail crossmember and overlapping leaves it too high.