Otto A.Müller - The current flag is a green over red horizontal bicolour.
In its centre is a white lozenge with black edges and black dotted capital
letters "O.A.M." inside.
I spotted this flag on 16 March 2007 in Hamburg on top of companies
office in Hamburg Domstraße 11.
Klaus-Michael Schneider, 18 May 2007
image by Jarig Bakker, 17 Feb 2005
O.A. Müller, Hamburg - green flag, over all red cross formy fimbriated
white; white diamond, black "OAM".
Image after Brown's Flags and Funnels of British and Foreign Steamship
Companies, compiled by F.J.N. Wedge, Glasgow, 1926 [wed26]
Jarig Bakker, 17 Feb 2005