G'day folks,
I'd think that Kirby, Doutty & Wicks was a
subsidiary of James N Kirby Pty Ltd - note the line 'A Unit of the James N Kirby Organisation'. James N Kirby was a very diversified company, with quite a few 'operating divisions'.
Note also the list of 'occupations' in this Bio of JNK - and it's by no means exhaustive!
http://adb.anu.edu.au/biography/kirby-sir-james-norman-10749