Hi Finches,
That is quite a marked difference isn't it. I must admit that I don't have a great collection of Australian stamps as we got here too late to start from a reasonable date.
We just have a booklet collection plus some odds and ends picked up whilst I was with the P.O.
For instance these two blocks of the 1972 Pioneer issue, (both with the blinkers flaw) with quite marked shade differences, particularly in the background.
Cheers
Ron.
