Try this: http://www.thomann.de/gb/tambourines.html?ls=100
They have what you are looking for. About halfway down the page is the LP191 Cyclops Jingle Ring. It looks like it would fit on 1cm of rod. I know the store is in Germany, but that's a lot closer than the US. Be about 30EUR or 25GBP shipped. That sounds good I guess, considering I only am familiar with dollars!