Yes, EUAT is the code for European Union / Austria.
This pistol was deactivated according to the 2016 EU Deactivation standard.
The combination of the crown, artillery notch and DWM military acceptance markings is strange, though.
Frame: DWM 1917 Navy
Receiver: DWM artillery
Barrel: post 1918 replacement
Chamber: some royal crown
Toggle: Mauser
Grips: used toilet seat
I'm going towards a guards gun for the Erfurt arsenal toilet building
Even stranger is the amount it brought at auction: 1100 bucks….