Hi Mark & welcome to the Board. Obviously I am also from the U.S. & even with 38 years of babbling in glass cannot match the European talent here. I do though suspect you are in all probability on the right track with Behemian...the who part though may be difficult...I would suspect a timeline of anywhere from late 1880s to maybe 1910. Wish I could help more, but I am sure others will jump in with better than I have to offer.
I envy you that you can tell the different ABP companies & designs. I never mastered that even though I have the Boggess, the Evers & the Corning Farrar/Spliiman references. Just last week I picked up a tankard the size of a small car that the shop thought it was Clark, but I was not convinced...bought it anyway just in case. Thought it may be Bergen. Who knows? Ken