Heli, what is the serial number on the camera? It should be a letter followed by numbers, perhaps embossed in the leather.
If there is a Zeiss lens, the serial is also useful, though most Nettars came with numberless Novars.
Which 120 format is your Nettar? I think they were made in 6x4.5, 6x6, and finally 6x9 as the original poster's.
Nettars are OK, but Ikonta's are a step above in terms of quality. Super Ikonta's add a coupled rangefinder at the cost of much size and weight.