To my knowledge, DWM using the “asb” headstamp is the only case maker of this type of case in 9 mm Para.
DAK’s comments on the position of the line are interesting. I had not seen enough of these in my collecting life to spot that variation. It would be fun to find a full box of all the same lot, and see if the line is struck at random. I cannot imagine that it is. I have only the one in my collection, which I haven’t checked this evening for positioning of that headstamp entry, and don’t recall ever having a duplicate.
I opened my room for another reason, so checked my round. It is lot number 41 of 43, and the
line across the headstamp is like DAK’s Lot 40, separating the “asb St+ /” from the “41 43” entry.