eBay and Craigslist finds

Renak comes from the eastern part of Germany, somewhere near Chemnitz

http://www.disraeligears.co.uk/Site/Renak_derailleurs.html

Right now now only have hub dynamo's / dynamo hubs and they are located in northern Germany, Itzehoe in Schleswig-Holstein

http://www.renak.de

renak was the biggest hub manufactor in the GDR and produced near Karl-Marx Stadt.
diamant frames where build in in Karl-Marx Stadt now Chemnitz.
They where build in the same special purpose machinery manufacture like textima sprint frames.(Michael Hübner rode textima in the 1990's sprint finals)
the race frames didn't come from the normal factory.