A ”Joddler” puts a step in the edge of a body panel so you can overlap it with another panel to create a nice joint when the panels are welded together, rather than just butt welding them.
You can buy these in both vice mounted and hand held versions, but I made this simple yet effective one some years ago when I was repairing my ‘66 Hillman Superminx estate. No longer got the car, but still got the joddler.
I thought it might prove useful to you guys doing bodywork.
Find yourself a decent 4 inch long domestic door hinge and weld two strips of the same gauge metal that you want to joddle, one to the outside edge of the hinge and the other to the inside edge of the opposite side of the hinge. Check the photo and you’ll see what I mean. When the hinge is closed there should be a slight gap between the welded strips. This will be the amount of step you’ll get in your joddled panel. About 2mm should do it.
Put the hinge in the vice and drop the sheet in. Squeeze it up and Bobs your Uncle –job done.

-AfghanMan