Gatorboy. I am an avid detectorist and starting to get a fever for this bottle thing. The black bases on the broken pcs look familiar to me. I found an exact black base shard like the ones you posted. There was some pipeline construction taking place and an area was clear cut and all debris was removed. The soil was a little sandy and after a rain i found a pc like yours and on the bottom i saw the letters "BRI". I carried it around for a few minutes because i had never seen a glass shard quite like it. I dropped it on the ground later. Now i kind of regret leaving it there. I am planning to do some privy digging there and who knows, maybe i can find a whole pc