Help With Early Great Britain

I have a Great Britain type A1 I'm trying to identify. There's a series of possible catalog numbers for this type depending on perforation, watermark, color... The problem I'm having is that I believe that the stamp I have is either Scott No. 8 or No. 9.

The difference between these two stamps is that No. 9 is re-engraved. The Scott catalog has a description of the re-engraved stamp but a picture would be worth a thousand descriptions.

Can anyone point me to a website that would show the differences between the original and the re-engraved stamp?

Eric