This issued were printed on thin and thick white paper. But the 10$ value only existing on thick white paper. If you have another type of a paper it's a forgery, but actually I believe it's more chemical bleched. Maybe to remove strong toning / yellowing.
The paper and color are quite different and the design is only a very bad imitation. I saw many forgeries of this stamp, this one belongs to the worst type and easy to judge.
Note to the buyer of this stamp: Please let it expertize by AIEP (http://www.aiep-experts.net) or Experts & Consultants Ltd. (contact is Mr. Poon) in Hong Kong.
Yes, that's right, every stamp has individual field marks. Also the print was quite rough. This is not what I'm talking about.
This stamp in the auction has the wrong color and the print is too unclear, please just compare the sharp lines in the sample of the one cent stamp (the block of 4) with the blurry lines in the two cent stamp.
Sure you are free to believe that this stamp is not a forgery. You can also believe the earth is disk and not globe. You are invited to ask other experts for confirmation. The contact of other experts you can find in my post earlier.