i found more on this pressure suit
it's from Drägerwerke but not Watanzug, it's the "Leichter Druckanzug" model 223
Drägerwerke were leading manufacture for diving breathing equipment in Germany 1930s
The Reichs Luftfahrt Ministerium order them for to deliberate a pressure suit in 1935
RLM demands
01. Internal pressure: 0.8atm, safety margin three times as much.
02. Shape and size for a person 1.8m tall.
03. Suit should be partitioned to simplify the donning.
04. Use of hands and sight shall not be hampered to allow easy landing and take-o.
05. Suit shall be electrically heated or the heat of the exhaustion pipe should be utilized.
06. Closed-Circuit-Rebreather system.
07. Fogging of the visor must be prevented.
08. Freedom of movement.
09. Rescue-exit with parachute must be possible.
10. Fail-safe system.
11. Radio communication inside the suit must be available.
12. Domestic components should be used, i.e. production independent of foreign currency.
13. Light weight.
At Drägerwerke Dr. Hermann Tietze, chief engineer for diving apparatuses start R&D
the first soft suit and hard suit were unusable for RLM need
but over the war Drägerwerke produce better and better pressure suits.
source
Under the waves, above the clouds.
A history of the pressure suit.
Alexander von Lünen
a Dissertation publish 2010
to find in internet for free.