That was originally what i thought too but if you check out this link for the similar Doll-E-Toy bottle ( or in case this link is not working, just go to ebay and search for Doll-E-toy bottle), you'll see the same notch. The notch on my bottle may have been chipped, but I think it originally was machine made http://www.ebay.com/itm/A...mp;hash=item1c466653b1
I always heard that these were doll bottles, though I was never quite sure what the notch was for. My first thought would be some part of the doll that it fits onto, though that would look kind of strange on the doll's end when the bottle wasn't there. The notch is definitely original though, most if not all of those bottles have one and that would be an extremely unlikely break, almost physically impossible.
Well if the notch was made on an Automatic Bottle Machine the notch would have been made in the guide ring that is held in the neckring. a tr'ickie thing to accomplish, The finish seems to be for a flat cardboard cap - s0 that makes me think of a dairy product, We leave in a couple days for Florida, so I will be on the road for three days. I would like to see one of these notched bottle tops to study the surface to figure it it was made by the tooling. I am sure they aren't worth big bucks, but no one else seems to give us any clus on the noitch creation, I like to examine strange marks in glass products, so this is still a bottlemystery! RED M.