I have two questions. I own a very old 13 cm by 18 cm Technika with serial number 3241. When was the camera manufactured? The second question relates to my Technika III version V. I can find no serial number. I think that I have looked everywhere, even under the accessory shoe. There were some partly legible numbers on the cam before I removed it (along with the rangefinder, etc. in order to lighten the camera for field work). There is no evidence of filing or grinding off a serial number. Were there cameras manufactured without serial numbers? And, if not, where should I look?