velomaniac
MacRetro Rider
Personally I use these on my retro steeds, not authentic but easy to set up and good value to quality ratio. you can sometimes get them even cheaper on ebay.
http://www.amazon.co.uk/Raleigh-RKD506- ... B0043QNLPI
http://www.amazon.co.uk/Raleigh-RKD506- ... B0043QNLPI