Early 1970's Bulova Astronaut GMT flyer

What is cooler than an astronaut? A spy pilot flying at bullet speed near the edge of space, wearing an astronaut.
The cold war was still in full swing in the early 70's, and the very secretive 'Skunkworks' division of Lockheed Martin at area 51 had already produced the groundbreaking A12 Blackbird spy plane.
Flying faster than a rifle bullet (mach 3.3), and near the edges of space, it was quite demanding for their pilots. And their watches. When fuel was low, airconditioning had to be turned off. Cockpit temperatures could run up to 60 degrees Celcius. Mechanical watches (worn outside of the pressure suit) could not cope with that. Along with G-forces, pressure changes et cetera. So the CIA ordered a special Bulova Accutron 'Astronaut' watch that was issued to the pilots. The Accutron ran on the principle of a tuning fork (before quartz watches were invented), and were very accurate. Nasa also embraced it, and at least 46 space missions used Accutron technology. This is a design based on the early 70's version of this watch (V4). I just like it a bit better than the original one.
I don't know if this watch was actually issued to the SR-71 Blackbird (the successor of the A12) pilots, but it sure is a cool story.  What I do know: Elvis Presley used to wear one too.

Now, the watch itself. What a masterpiece, if I say so myself. Fully working 'Flyer GMT'. Meanig able to check THREE timezones with an adjustable 'reference' GMT hand, and a rotating bezel. I got rid of the space taken up by rims et cetera, so the watch face itself uses maximum space, while maintaining the functional rotating bezel. I also spent a lot of time on visual feedback. You'll know exactly how far you are off from local reference because the watch tells you the delta (difference) time. The static, colored arrows on the bezel give away what region to tap for GMT pointer (red) and bezel (grey). And just a tiny bit of patina (scratches) to make it era correct.

Here's a quick manual:

Start
On start, you'll see the time as usual. Hour and minute hands just show the time. The reference -or GMT- hand with the red arrow shows the 24 hour time (which you can read on the bezel). The normal hours rotate every 12 hours. The reference/GMT hand in 24 hours.

Setting a second time zone
The bezel shows small (static) arrows. The red arrows (similar to the color of the GMT hand) at 3 and 9 turn the reference/ GMT hand.

I live in the Netherlands (GMT +1), and I want to know New York city time (GMT -5). so, for me, New York is local time -6. (It's the difference with between my local time and NYC, so do not make the mistake of calculating +1 and -5 as -4)
Every time you press the buttons, the watch will give feedback of how many hours plus or minus you are from local time. When I reach delta (change) -6, the reference hand will show the New York 24 hour time on the bezel. Minutes are as usual.

(Quickly) Checking a third time zone
By turning the bezel (6 and 12, grey arrows), you can quickly check a third time zone. The only tricky part is that you have to calculate based on the 'reference hand'. So if you set your second time zone to New York, that's your new reference time.
If you want to calculate the time in Beijing, you have to take New York as a starting point and know the difference with Beijing. New York is GMT -5, Beijing is GMT +8.
That's a delta (time difference) of +13 hours. (The watch will translate that to -11)

It works. But it's not something you want to do every day, for sure. Don't forget to return your bezel right after checking your third time zone, or else you're in the woods. You can always repair it later by changing back the bezel to your delta zero time zone, but else you'll be calling New York at odd hours.

PS: Mechanical watches work a bit differently, to make things extra confusing. On a Rolex GMT Master II, you change the primary hour hand, not the reference/GMT hand. And you move the date as well. It's just a lot of hassle with mechanical watches...but cool.

Extra, extra confusing: there's also GMT 'caller' watches, where the normal hour hand and the 24 hour (reference/ GMT) are connected. You can move the hours, but the GMT hand always moves along at half the speed. You cannot set them independently.

PPS: I spent lot of time on this one, so this watch is ©. Please let me know beforehand if you want to use it, and what you want to do with it. And credits for my work are the least.

PPPS: I ran into problems with maximum animations. Again. Tried to do everything with dynamic shadow animations, and then suddenly everything goes haywire. Bummer. Cost me a lot of extra time.

PPPPS: I'm not quite pleased with the markings on the watch. The astronaut has a very bulbous and thick glass, so if you don't look at it at a straight angle, it deforms. this was the case in my source material. Maybe I'll update it, but it doesn't bother me that much.

UPDATE: added haptic feedback when setting GMT.