Vintage Waltham 1 7/8" Dial USAF AN5743-T-1A Aircraft Clock 8 Day Not

Offering this Vintage Waltham Type A-13A Aircraft 8 Day Clock in what appears to be working condition. The knob on front moves and winds the clock and the second hand is moving. I'm not exactly sure how these work but here is the story on it. My grandfather worked at Ontario Aircraft in Ontario, CA in the 1950's so I am guessing it came from there. He passed away in 1964 and his things were packed away until recently when I had to empty the property near there. As a result, I can say it has been stored away since 1964. The printing on back is hard to see but this is the last one of several of these so I am basing the model off the others I had. Very cool old piece. I would not know if it would need serviced or cleaned. Please zoom on pics as they are part of the description and ask any questions before bidding/buying. If there are any issues upon delivery, please contact me before leaving negative feedback. I will be happy to try and resolve problems, as I am easy to get along with and my policy is to always "do the right thing", so bid/buy with confidence. Offers Always Welcome !