Check this out. I haven't tried it myself, but it's a way to use lapped screwed fastenings of a patch panel and a true butt joint.
One comment I have about it, is that the metal gets deformed as he goes along as opposed to a well fitted butt joint along the whole length of the patch weld.

Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.