China Red Revenue Stamps

Hi I'm very new to this, I have inherited a stamp collection and in particular am interested in these stamps as I have found a few articles online suggesting they could be worth something? Like I say I am no expert though so am not getting my hopes up at all but would be very grateful for some opinions on them!

See:

https://en.wikipedia.org/wiki/Red_Revenue

Mandmurf,
YOu have Chinese Scott design A13 with the a bype (The 2cents. is on one line, with period at the end of cents.). The SCOTT # is 79. It's not one of the 79 variants but still carries a catalog value of $400 for used stamp. Nothing to sneeze at there at all. You image is pretty poor, so it's hard to comment on condition, but it looks to have some pulled perfs, and maybe centered a bit high, but should still have some reasonable value. These are revenue stamps that were overpinted for postal use, issued in 1897. Nice find.

Thanks very much for your replies, I know I am new to this but I am finding it all very interesting!

If you have time I would greatly appreciate your opinions on the rest of my collection - I have attached images to a separate post.