478, 496 and 512 all three have the same design but not on this color. It is hard to tell by the scan but it can be reduced to two stamps depending on solid or crosshatched panels, hard to tell by the scan. Thanks for your reply.
The truth is within and only you can reveal it 18 Apr 2017 03:25:00am
re: Austria
I haven't any doubt that it is a color changeling as I have seen this many times. I think there must be something in the makeup of some Purple inks that react with something common that may come in contact with it. Possibly something in the local water like Iron etc.
or something in a certain soap. I've seen this changing from Purple to Blue happen mostly on the stamps of Portugal circa 1870-80's
