The Sander Company was in Kaiserslautern, Germany at some point before WWII, and was in Augsburg, Germany (suburb of Munich) at some point after WWII. The earlier Sander CC I've worked on was one of Fred Geib's, from Kaiserslautern, a small-but-potent horn with 4 string-linkage rotors. It is in a collection now.
The newer Sander CC I've worked on was made in Augsburg, and looks like a yellow-brass version of the copper tuba, but with traditional rotor placement. The wrap was very compact, making it difficult to service the rotors, but it played like a dream, a compact-but-potent player.
I would guess that Sander was eventually bought-out by either Boehm & Meinl or Wenzel Meinl.