You might want to check out one of Canada's leading stamp dealers - he deals almost exlusively in revenues : ESJ (Erling) vanDam. I have no connection to him professionally, but I do buy from him at shows now and then. He's very helpful in identifying odd (to me) items and has helped a lot of people I know to build lovely collections.
http://www.esjvandam.com/I bet you might even find the stamps pictured in the original post, or ask Erling for some pointers about them.
Those folowing this thread might also enjoy reading some of the issues of the BNAPS Revenue Study Group I mentioned previously.
http://bnatopics.org/hhlibrary/news...rs/n-rev.htm (the online isues only go to 2004 - newer ones are restricted to members of the study group)
These revenues can be a very interesting area of collecting. I know that I have to keep resisting the urge to delve deeper.
Peter