I wanted to ask the experts if they can help me identify what I purchased. I picked up a Gruen "Airflight" jump hours watch that I need help with. First, can anyone tell me the reference number(s) or name for this or any Airflight? No one ever publishes the reference online. Secondly, every watch of this type that I have seen has been 35-36MM dia. and this one is 42mm. My watchmaker has looked it over and serviced it and tells me that it all appears correct. So, anyone have an idea of the story behind this unique piece?