I have a very rare Gruen Airflight Jump Hour that I would like to get repaired and serviced. The movement of the Gruen is the common N510SS. Complexities come with the jump hour part of the watch. Is there any information out there on servicing the jump hour portion of this watch? The only thing I can think of is purchasing the book "The Gruen Watch Repairer's Reference". I am not sure though if this would have any information on the Airflight or not.
Any help will be appreciated.