I've seen a few bubbly masters but I agree that it's hard to tell without seeing the poles. Looks like it could be a sparse brushed patch. To get bubbly, all it took was a little accidental (or purposeful) overheating of the furnace.
A couple more pics; but I'm not sure they will be much help. Poles proving tough buggers to photograph....and one pole, of course, has a big 'ole chip right on top of it. Best I can describe is it looks like a "false eyelash".
That second picture shows your eyelashes. Master and Akro were the two that normally had eyelashes and the base glass is right and the white strip is right for a master brushed patch IMO. The transitional cut line creases normally have a spidery pattern to them instead of the eyelashes, and transitionals almost all swirl, so I'm leaning away from that possibility. Plus it just looks like American glass to me. Could be wrong though.