First Allocation of Macquarie Plain

[songenaz]

Hello
I have a poor knowledge of what is possible or not with First Allocation Postmark...
Please look at that.

42 on perfs 12.JPG (5.88 KiB) Viewed 1785 times

First Allocation Of Macquarie Plain on 1 D Carmine, perf 12, SG70 (1865)

How is it possible to find such a mistake as 2nd Allocation opened in 1861?
Is It a forgery?

What's your opinion?

Thanks for your help

Regards from France

Laurent