
Hi timbres667
Here is as scan of all three
It seems strange that this one has an imprint, from the front the printing is raised, from the back it is recessed, Maybe that is what has happened, anyway the stamp is not damaged, so it is just a curiosity.
All three copies from the same thrift shop batch have varying parts of the post mark.
I believe it says "Victoria and Melbourne Centenary 1934-35