Captain Darren Crabb is an authority on these, and has been known to frequent OF. He has authored a book on them published in November 2015 that is unfortunately difficult to find, but you may still be able to. They were made by Birks, Breitling, Candino, Lemania, Omega, Rodania, Wittnauer, and even Universal Genève over the years… all according to RCAF specifications.

