Sauer & Pieper go way back as Pieper was German. Paul Steuer served his appretniceship @ Peiper in Lüttich/Liège, and very well may have on his walkabout worked a stint @ Sauer, before go to Berlin to be a partner @ Oskar Geiger / Geyger, before Gieger / Geyger looks to have passed this life in 1919.

So the Pieper/Sauer footprint in Berlin was more than likely centred around Oskar Geiger/Geyger with Paul Steuer as the Keystone. I just need to check all the addresses.

Hochachtungsvoll,

Raimey
rse