It can be a fairly daunting task when trying to find vintage lightweight parts for a project. There are places like Velo Orange that carry wonderful parts for Porteur style cruisers and of course Rivendell Bicycle Works that carries some great touring parts and great little odds and ends that are hard to find anywhere else. However there really is not a great source for vintage lightweight parts. You can certainly scour Ebay like a mad man, but I am sure some people would prefer something else, and this could be a good answer, if you live in Hungary.
Check out Matuz Master and their nice collection of vintage and modern parts.