I've seen that on hoods. Can't remember what hood but it is more of a "flowing" material rather than a sheet stock. I guess I now have to ask myself "what's it for". I guess it was used as a semi adhesive to eliminate oil canning of the hood?, or slapping the braces?, because they didn't weld, bolt or rivet the hood to the braces? If it were me I would base my decision on how big the gap is. To use sheet stock bonded or squirt sealer in....or nothing.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn