The Nikkor name was first applied for in 1931 and was registered in 1932.
The first series consisted of 7.5cm,10.5cm,12cm,18cm in the Tessar
type for general photographic use and Aero Nikkor 50cm and 75cm in
the triplet type design for aerial reconnaissance.
This one might have been on Konishi's Lily or Ideal of the period.
Strange enough, the serial number on this particular lens is the same
as the 10.5cm Nikkor depicted on the Nikon 75years book.
See the detailed photo of the lens