All I have to say is it will be interesting to see what the SEC says about that Form 10 sitting out there. As you pointed out the history by itself would require further digging into other areas including shell status and share issuance. An inactive registration would certainly draw interest.
My opinion is there is no doubt it was a shell, and just being inactive would put it on the pile as a shell. Unfortunately the SEC doesn't spell it out that way. It certainly would cut a lot of them out if the SEC included a line about inactive registrations for a specified period of time. But as I said before, it seems the SEC doesn't want to draw exact lines and left it as transparent as pudding and subject to their own interpretation... lol