Where Are These From?

I'm having some trouble finding the value of a couple stamps. I have no idea where this one is from.



And I believe this guy is from China but I can't find it for the life of me. It's similar to a China 253-A29, but the color is a Olv Grn or Drk Grn.

Top one is Greece 1927 Scott#324

The Chinese is 1926 #275 olive green

Thanks a bunch, jamesw. I'm still getting the hang of this book! That China one is pretty far removed from where that group is originally listed. :)

In the Scott catalog, after the pictures and values are listed, always read on to the end, where sometimes it will say see number so and so for other versions of similar design. Like this Chinese stamp, on the early stamps the pearls at the top are shaded with fine lines. Then there are other differences in the Peking and London printings. Chinese stamps are really fun with secret marks to check. It really makes it interesting to get the right identification.