Delaware River Shoreline Sandbar Glass Finds

[steamjunker]

I walk up and down the shoreline of the delaware river without a metal detector, even though I have permission from DCNR, to many obstacles to even try and use one. I'm on the PA side, last years flood and recent flooding did a number on our side, trees all over the place like matchsticks. Anyways I search up and down the shoreline for driftwood, "sea"glass/river glass, plus anything else interesting. Found these two pieces yesterday. Piece of a 17 or 18thc. black onion bottle and the other one I thought was a broken bottle neck and top, but I just figured it out,a piece of a threadless insulator,my first one or piece anyways. Haven't been able to find any insulator close to this one, must be a uncatologued variety.
Any Help on the threadless insulator would much appreciated.