Contessa Nettel 6x9 with Nettar Anastigmat 1: 6,3 10,5 cm

•      A prototype?
•      Contessa Nettel N ° 388 159 Nettar-Anastigmat 1: 6.3 F = 10.5 cm
•      Derval closure
•      Aperture: 6.3 to 31
•      Shutter speeds 25-100 and B - T
•      Plate camera
•      Weight approx 512g
•      Prototype?

The lens number is engraved with 2 different sized numbers, see pictures.

In good used condition, looks like a prototype - it could also be a hobbyist pieces, many parts made of brass handmade, upholstered in soft leather, black lacquer, the pull mechanism is completely a self-construction, the shutter speed to run cleanly, no scratches on the lenses (optics), look at the pictures.