I took some pictures of some of my MB149 nibs and uploaded them here:
https://imgur.com/a/LIVjdw5
The nibs are in chronological order: 14C tricolor nib from the sixties (BB+ width), 1970s tricolor, 18c in smaller numerals (B?/BB?), and a bicolor 14c nib from the 1970s.
Bookmarks