There might be a long and newman hood out there somewhere, but these were made decades ago. Not sure what you mean by vented hood dam as my belief is all of the body panels duplicated the stock body panels.
as you have apparently already found out, the ignition assembly was mounted with bolts that incorporated a hex head that snapped off when the correct tightness was achieved during installation.
I think the easiest removal process involves a Dremel tool with a fiberglass cut off wheel. Using it, grind a slot in the bolt stubs that will accept a flat blade screwdriver. That should do the trick.
but, there are few situations that require that assembly to be removed. Can you tell us what your motivation is for removal?
there may be other approaches instead of the trouble of removal