I have 5 of these bobbins (I didn't think I had that many until I just counted them). I'm not sure mine are as old as yours, Byron, but mine are all probably over 25 years old.

None of mine have the pretty green clamp that yours has, but are much the same otherwise, although mine each have a nice "J" and a "D" stamped on opposite sides of the bobbin where the thread is held. (I really like the green on your Bobbin!)

I can't say mine are my favorite bobbins, although they are certainly easy to thread, and while I have used mine continuously to tie with for all these past years (along with a smattering of other bobbin brands) I can never recall cutting a thread with any of them that is a fault of the bobbin - which is amazing considering the many flies I've tied with them.

John

P. S. It would be interesting to know whether ceramic bobbin tubes could be made like these bobbins.