Voigtlander Vitessa - serial number location

[npeters]

Hi - I have found a beautiful Voigtlander Vitessa, I think its the A3 variant. Can anyone let me know where is the serial number location?

Many thanks

Norman, Canberra, Australia

 

[npeters]

Vitessa

Vitessa

No number is visible on the chassis, at least anywhere I can see..

 

[npeters]

Looked again

Looked again

Ahh, I now see a serial on the lens - 34836** lens - but nothing anywhere on the body.

 

[npeters]

There is definitely no serial number anywhere near the film chamber / rails etc.
(It is an f2 50mm Ultron model, with an attached Voigtlander UV filter that I can't get off - I understand it's a bayonet fitting, but I cant move it at all.)