Genuine

Forgery A

1) The E of OLDENBURG is much shorter at the top. 

2) The cross at the top of the crown reaches down to the middle of the orb over the crown. 

3) The tail of the R of OLDENBURG curls up.

4) There is a clear pearl at the right of the crown.

5) Note the gap and position of the top right ribbon ends.

6) There is a dot to the left of the right 1 and to the right of the left 1.

7) Note the odd shape of both 1s.

8) Note the sizes and positions of the pearls at the very bottom of the stamp.

9) There is a clear + in the circle above the cross in the lower left fifth of the shield.

Click image for plain view

The design is very hard to see. 

The cross at the top of the crown does not reach down to the middle of the orb over the crown. 

The number 1 is poorly shaped on both sides.

The pearls at teh bottom are too large.

The crown detail is very poor in general 

Bibliography

Grosses Handbuch Der Falschungen Lieferung No. 17 Oldenburg, text by Otto E. Stiedl, Photos by Fritz Billig

Album Weeds by Rev. R. B. Earee

Distinguishing Characteristics of Classic Stamps, Old German States. by Hermann Schloss.

The Serrane Guide by Fernand Serrane

The Forged Stamps of all Countries by J. Dorn