The nib described comes from a later epoch, presumably after 1945, and does not fit the production period of the IIIb of 1932 to 1934. Period-original would be a so-called b-nib with b in a triangle. As an acceptable alternative, a No. 4 nib with the 4 in the Montblanc star circle comes into question. The writing behaviour of the fitted nib, butter-soft and flexible, also corresponds rather to the characteristic of the 1950s.