I've never considered any jabo to be a true single seamed marble before, like the hand gathers. Please correct me if I'm wrong but I thought the jabo's "appearance" of a single cut-line is actually two-seams completely folded? I suppose i'm guilty of always thinking in terms peltier, but I also see rainbo's with what looks like one cut-line, and is actually a complete fold.
Thanks for sharing the alox shear photos, hope you don't mind the side by side.
Could the alox shear also be the lawrence glass novelty shear of 33'? They look very similar and were made to dispense two marbles at a time, correct?