Beautiful watch and great provenance..

Vorwärts & Nach hinten (forwards & backwards)
 

https://www.hausmann-co.com/wp-content/uploads/2014/04/movmento-lange-su-orologio-pilota.jpg

Thanks - did a quick image search on the subject but obviously didn’t look at enough examples..

Please forgive this question which probably has a very obvious answer but why does it have S & F on the regulator rather than the usual V & N?

Not sure if these pictures will be of any assistance - I've realised the Stowa face is an off-black (which I like) but not a good comparison if the other face is very black. The top two were taken next to a window with natural light - taken above and at an an angle to maximise reflection. Bottom pic taken in bright sunshine. All I can say is I’ve never felt readability is an issue..

Have you looked at the Stowa Friends section on the Stowa site? There’s a map with owners of their watches who are happy to show them to prospective buyers; there’s two in CO - including a 2016 Flieger - assume the AR coating will be the same as a newer one and could help you make the decision. 

I’ll add some more pictures tomorrow taken in daylight. Sadly I don’t have a Sinn to compare - perhaps one day! 
 

Funny you should mention the Hamilton - I am planning on getting one for one of my children so will have a good look at the reflection you mention.
 

One of the things I love most about my Stowa Flieger is the legibility of the dial - I’d say the ability to see clearly in all light conditions is really excellent. The blued hands are an extra bonus and add a hint of colour. The picture was taken with bright strip ceiling lights. 

You won’t regret getting one!