Roger, I haven't seen one of John's locks for many years. I bought one of his longrifle kits back in the last century, and assembled the lock as a kit as well. It made up into a wonderful lock that served me well on the rifle and I'm sure is still going strong with its current owner. The lock does not or at least then did not, have a fly in the tumbler, but with a simple trigger still functioned well. I wish I had some pics of that rifle. It was a Leonard Reedy styled rifle in .40 cal and I enjoyed it a lot. Perhaps Hugh Toenjes could add to my comment, since he bought the rifle from me.