No problem on the comments Tim. The plug is flat, not dished and no signs of threads. For what it is worth the plug is the shape of the horn - the horn was not shaped to the plug. I believe the tip is an adjustable powder flask tip, not a shot tip. I do think it was was added at some point in it's working life. The horn is nicely made, not rough like some I have seen. Collected "off the farm" in the 1930's by my Grandma so it is at least that old!