Australia Sideways Watermark

This was a little pricey, but I needed a copy for my collection. Sideways watermarks are rare, but not really for this one. Identified as Scott 51b, ACSC 33aa, Mint Never Hinged.

Front Scan:


Through Scan showing full sideways watermark, plus a partial one:


I wonder about the vertical perforation spacing at the top of this stamp. It appears to be different than all of the others. Any comments from our Aussie friends?

My example is used & IF genuine is rare . But I'm not confident .

Thanks for the example Al. It looks like the same perforation pattern, so I guess that was the rule for these items. That cancel does look a bit dodgy, though.

These are new to me, I do not recall seeing them before.
I have seen examples of "comb perforator slippage"
generally in the last line of punctures before the table hit the stop pin.

Aussie Al,

The perforations are normal. The slippage occurred anywhere during the vertical travel of the perforator. Here's an annotated image showing that there is symmetry from one side to the other on your stamp. Nothing suspicious. I applied one line parallel to the top perforation holes then copied it 3 times replicating the top row thus confirming no suspicious shifting of the perforations on only one side.



Cancel is a bit strange looking but it seems to be a steel type with relatively sharp corners on the letters. Genuine, but might not have been contemporaneously applied ergo pre-dated.

You'd have to identify the date-stamp to determine its correct period of usage.