First I'm not Hank, I'm just a good friend of his. Hank is the owner of Bulletproof.
All Metal Dell'Otto covers were originally Bulletproof exclusives, just like the DKIII Dell'Otto covers. Since Dell'Otto, was appearing at LSCC he called Hank and asked for a favor to print 1,000 convention virgin exclusives on top of the 1,0000 Bulletproof virgins that were already ordered. Without that favor requested by Dell'Otto there would only be the Bulletproof virgin in existence. So Hank agreed, with Dell'Otto getting 500 and Hank 500. In my opinion the rarest is the Bulletproof Virgin signed by Dell'Otto, it'll have a special cgc label, and a surprise.. Print runs are the same on convention and Bulletproof virgins, both are 1k.
Future covers will be Bulletproof exclusives, I don't know what the backs will look like as I haven't seen them yet.