Unsurfaced Paper With Perf Os

Hi all
Heres one for the KGV experts, this stamp here is a single wm 1&1/2 red die 1, it also is either unsurfaced paper or coarse mesh paper with a perf os, & as far as I can make out an unlisted variety. between the emus neck & kings head is a break in the lines & under the A of Australia at right. BW#ACSC list a unsurfaced& coarse mesh paper, but no reference to the additional perf os or possible variety. The 2nd scan is just for comparison,when running your fingers across both stamps there is a very noticeable harsher feel to the os stamp, any clues as to what this really may be, anyone?

Regards Jezza

The "OS" makes it an official stamp, with a completely different catalog number! I can not see the varieties you indicate because the scan is too small, but they may be due to slight under-inking?

Peter

Although I lack experience with Australian stamps, I remember seeing something, somewhere, about the Australian government/Post Office using up any poor-quality and/or recalled stamps for OS use.
That may be an explanation.

It could easily be a forged OS perfin on a genuine unsurfaced stamp. There have been many forgeries of the OS perfin recently.