Firmenzeichen

[sewer]

I have a question about printing firms during the inflation period 1922-1923.
One of my ancestors ran the printing firm H. S. Hermann, Berlin, which printed Papiergeld for the Reichsbank. His Firmenzeichen included HB, HR, HS, RH, and for Ro. 84 only, BH. I have 2 questions:
1. Are there similar codes for 1-letter Firmenzeichen? If so, which (if any) are associated with H.S. Hermann?
2. I noticed similar letters (RH, HR) on notes from the Reichsbahn Berlin series. Could these also be from H. S. Hermann?
Vielen Dank!