I have just bought a 30sqm in bad condition. I am trying to restore the boat to its original lines. I am told it was built by Vertens in kiel in 1937, but like you I cannot find the hull or registration number. Do you have any plans or blue prints or some old photos to compare?
I am sending an old photo of the boat but I am not sure if it is how it was built in 1937.
I think we may have similar boats.