Yes, Tab. It is one of our jokes at work. We use a can of Tab to show scale.
My boss feels, after researching and talking to some folks, that he could get $600 to $800 for the lens. He has offered it to me for $400. I can pay him outright, or just not log 34 hours of work (of which I already have about 20 logged and unpaid).
I really am in love with the sucker on principle, but without a flange or pinion, I think even $400 is a bit much.
Maybe I need to do some test shots on my 5x7 to see how much I really love it in practice. It could end up being nothing great.
Also, having disassembled this lens, I can say that it was originally built with the slot for the stops. There is internal hardware integral to the barrel that could not have been added later, and nothing looks to be added or modified at all.
I misspoke earlier. There are three groups, not three elements. The two front elements are glued together into one group. Additionally, from what I can gather, the two rear groups are flipped compared to Petzval's original design. Apparently, this is a modification that Voigtlander made, according to someone on the Wiki-thingy...whatever that is worth.