I posted a long while back about my Oaklawn 24" find that had no re-rings.
http://www.vintagedrumforum.com/showthread.php?t=30456&highlight=camco
I'm not sure if the link there will work, but there are pictures of mine on that thread.
There was another member with one, and now I found this one on e-bay. Here is a picture from the post, and an Item number, but I couldn't get the link to work correctly there. Item number 110983588990
It would seem that three might lend to a new possibility of no re-rings on a 24" oaklawn.