Have a look at this eclectic collection of roadsters from Brazil.
http://www.bicicletasantigas.com.br/
As expected, a varied assortment of german and english bikes. Stuck in the middle is this Hirondelle with the wildest set up I've ever seen. It's a shame the rest of the bike has been cannibalized....
http://pessoal.onda.com.br/
At the bottom of the page is a selection of adverts from the fifties describing this "retro-direct" gearing system. Very cool and a nice website!
Warren Young
Toronto