They probably have been in pocket watch cases too. These B-watches have been made for the German Luftwaffe by only 5 manufacturers
A. Lange & Söhne
Laco (Lacher & Co)
Stowa (Walter Storz)
Wempe (Chronometerwerke Hamburg)
IWC
and contained high quality pocket watch movements:
Lange & Söhne: cal. 48/1
(due to limited capacities watches have been assembled by Huber/Munich, Felsing/Berlin, Schieron/Stuttgart, Schätzle & Tschudin/Pforzheim, Wempe/Hamburg).
Laco: Durowe cal. D 5
Stowa: Unitas cal. 2812
Wempe: Thommen cal. 31
IWC: cal. 52 SC
Due to the specifications of the RLM (Reichsluftfahrtministerium) all B-watches had the following features in common:
- A case diameter of 55 mm
- Marked on the back with FL 23883 (FL = flight, 23 = navigation)
- Equipped with large crowns in order to be used with gloves
- Hacking movement (the second hand stops when pulling out the crown / essential for a precise time setting)
- Breguet balance spring
- Regulated and tested as chronometers
- Long leather strap (to be worn on the sleeve of a flight jacket).
I have to admit that Ie never seen a Unitas 2812 in a pocket watch but there mights haven been some.