I played on these in the 60s but they could have been older. Not something that moves a lot except between practice and concert auditorium a couple times a year. Old style arms. Ludwig Symphony model.

Pedal was supposed to make it possible to change pitch and there was an optional scale on the side, saying what note. But you still had to tune by ear. It was a close point to the right pitch.

Tension arms on the outside was for better sound, less equipment inside the bowl.

I had fun with those back in school too. I'd love to have one or 3 or a kettle drum (s) LOL. I think my wife might feel differently though. :o Some seem to sell pretty cheap but these seem priced pretty well.

ludwig had a line known as Ringer from those look like them very pricy

http://columbus.craigslist.org/msg/3438834025.html

Must be the week for selling big copper drums...