I'm organizing my stock books and ran into a few mysteries.
I'm using stamp-world, SCW, Big blue, and simplified Scott and SG. Didn't help me.
The first set is not mentioned anywhere. Any idea what it is, and if it's genuine?
The first to the left commemorates nationalism of oil companies.
When was the original one issued, when was this overprinted issued, and what is the overprint?
What is the middle one, and what is the overprint?
The left one was issued without overprint at 1910. I think this one was issued on 1916. What is the overprint?
Any remark will be helpful.