Australia: George VI 2d Red Interpanneau Pairs

I only answered one of your questions. Yes, interpanneau pairs, especially imprint pairs/blocks have good value. You can do some googling for interpanneau imprint blocks for that series to get an idea of retail value.

This is subject to confirmation/correction, but I believe a fold/bend in the gutter is normal for this issue, as the press sheets were shipped folded over. However, it sounds like your example may have been folded along the perfs? I don't believe they were originally folded that way, and certainly should not be stored folded.

I'm not familiar with the pane/sheet layouts for Australian stamps. This is from memory, as my Australian gutter pair album has been in storage for over a decade; but from what I've seen in my basic collection of Australian gutter pairs, the perforations run all the way through the gutter when there's a gutter within the pane, but may or may not for interpanneau pairs. Again, that's subject to confirmation/correction from someone more familiar with Australian stamps. I'm just a general WW collector.

Interpanneau pairs are certainly going to fetch a premium over the single stamps.

Now Check out the selvedge with printer name John Ash . Aussie collectors get excited about these and that is a big plus , pity the gum has gone in the rescue , but keep the block all together .

however I think we have misread your posts. You don’t have the John Ash ?

OK, stamptracker I also misunderstood your original post. I thought you were asking about the block of 4 shown in your original post. Now I understand that was pasted in, and the stamp you actually have is at left.  My apologies.  I tried to provide the answer to the wrong stamp in the picture!

The left stamp is an example of a gutter pair from the Die II printing. That one has perforations all the way through the gutter, and that particular gutter is the same size as the stamp. However, I do not know the full layout of the press sheet. I do know that if you follow the gutter up, there will be a plate number and there will also be a red dot on the selvedge one column to the right and left of the gutter. People like me find the selvedge more interesting than the stamp.

This is a copy of the ASH Imprint with the thin paper variety. ACSC 188aa Thin Paper (0.075mm or less)

The note associated with the paper says the following: The thin paper variety (0.091mm including gum, compared to the normal which exceeds 0.1mm) shows the design being clearly visible from the back.

I have a digital micrometer to measure paper thickness as many German stamps have thinner and thicker paper varieties. It's very handy.

ACSC is The Australian Commonwealth Specialists Catalogue, sometimes know as Brunsden White (The publisher)

This is the block from the rear. 

The watermark really stands out but the design isn't obvious in the scan but is when held up to light.

To give you an idea of scarcity, a MNH copy of the thin paper stamp is catalogued at $200 each while the normal stamp is $3. A standard ASH imprint block of 4 is $20. The thin paper version isn't priced.

I've added images of the micrometer. In Australia we use the metric system but I've included the inch measurement for your reference.