Is This 90c Justice Official An O34, Soft Paper Or Proof?

Here's a 90c Justice Official stamp which has soft paper, not the thin or thin hard paper of Scott O34. There is no listing for a 90c Justice Official with soft porous paper. I would surely like this to be a new discovery of a soft porous paper 90c Justice Official, however don't think it is likely.

Given that the cancel is suspect. Given that the 90c Justice on soft porous paper probably wasn't printed at all. This is likely a proof that has been perforated and adorned with a faked cancel.

Oh, and what do you think all of the markings on the back are about?

Any thoughts would be appreciated!

What make you suspect the cancel? It appears to be ink mixed according to the then current formulas, as the linseed oil stain on the back shows. The marks on the back could be sellers notes.
There is another possibilty. It is known that Continental Banknote Company used several differnt papers in the printing of their stamps. This stamp may have been printed on one of those papers, although it does look like "thin, hard paper", it also shows the characteristics of a Continental stamp, like the clear sharp image and the well defined perfs like a Continental, having no fibers on the tips.
I have what appears to be a soft paper Continental Official, an O8, the 24C Agriculture. It shows the mottled effect of soft paper when held up to the light, and the face shows spotty inking like soft paper does. The back of my Soft Paper? 24C Agriculture has several different owners marks.

littleriverphil - thanks for your input and showing a similar example. Yes, there aren't the paper fibers you typically see on the perforation tips of soft paper issues - I was assuming due to possible reperforation (or just privately perforating).

The paper is very thick and not nearly as translucent as the other official stamps, but I haven't measured/compared the thickness yet.

The cancel is very bold and cleanly struck. As a cork cancel, I wouldn't expect the edges to be this clean - maybe it's due to a wetter or larger amount of ink on the cork.

It is possible that it could be a shaved proof, although it doesn't seem to have a proof like impression, and even the 1890 American P4 proofs have very sharp impressions. Until you send it in for expertizing, I'd say do what I'm doing with my O8 soft paper? and call transitional paper. I've got a 2 cent regular issue Scott 157 that is the same, not a ribbed paper, not a double paper as I also have both of those, and it is not like either. Continental Banknotes are difficult to say the least!