I have a running CoBra in my Crosley. Search Crosley CoBra on YouTube and you should find some videos.
It’s pretty obvious looking at a CoBra that it is made out of individual stampings that have been assembled and brazed together. I’ve attached some detail photos of my engine from when I cleaned it up. My engine is galvanized, which is a trick they used later to address the corrosion and leakage problems.
I have a defunct tin block I’d be glad to give you, but I’m in Wisconsin and shipping would probably be prohibitive. The dead version of the engine is pretty common, so I bet you can find one free or cheap in Florida.