Serial number DE9833829, located on a plate at the back where rear rack is mounted.
(Les Quarznica). When i bought it previous owner was using it with 26″ wheels, but this frame was clearly made for 28″ wheels (canti brakes mount height). The frame is very big so it’s looks like it was custom made for somebody very tall as the measurements are as follows:
There are lots of mounts on the frame and forks, its looks like touring drop bars bike for a tall person, the only original parts on those photos are frameset, headset and seat post.
Shown in the photos is how I have built it with coaster brake hub wheels,