I think a77impala is thinking of an adapter that attaches to your bars and then you can attach any cage to that adapter. Yellow Jersey in Madison sells them for about $15.

TA made a version in the 70s, they go for $30-$50 on ebay. I see one every few weeks.

The older ones without the bottles go for about $70, with aluminum bottles, about $150. They are on ebay about every 4-6 weeks. I would have had some cheaper but the moronic seller forgot to take me off the bidding block list (I was on because he didn't ship to the US, he said he would take me off but never did).

There are some repros on ebay right now from a seller who sells through his website too. He may have a source if you want to ask.

http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=011

http://www.sdbicyclegarage.com/index.html