I am still agonising over these.
Bob suggests the lower stamp of the OP is genuine.
Am I correct in assuming there are 12 different 2d POST PAID blues?
In my records, Forgeries of the above, exist in
Types B,C,E,G and H
Type B Forgery test is
No dots in corner ornaments
Type C Forgery
No vertical lines in background
The so called "genuine" stamp has no dots, and No vertical Lines
Genuine stamps have crossed vertical and oblique background lines
I cannot see how that apparent genuine, is so

Bib: Forged stamps of the British Empire . H. Bynof-Smith.