With regard to discussions on DDSG postal's activity from this thread :
http://www.philaseiten.de/cgi-bin/index.pl?ST=853&CP=0&F=1To all interested on this subject I would suggest this comprehensive book :
The private ship letter stamps of the world, Part 2, Australia-Europe-South America: by S.Ringstrom and H.E.Tester, 1976 ,Skogs Trelleborg,The bibliography used by the authors to write their work is shown below :
In the above-mentioned book, the only ORSOVA Agency
oval type marking is shown attached
@ March
[#1]Dear March
thank you for your advice of literature about this topic. Also the bibliography used by the authors Ringstrom Tester (1-12) is usefull. The list in the work of Hurt/Kelly 1950 mentions a few more (early references, only, of course).
Greeting
Heinz