www.freebmd.org.uk/ has Marriages Sept quarter [July/Aug/Sept] 1876, John GICK & Anna SWAN, with District: Stoke Damerel, Volume: 5b, Page 629.

You can order a GRO certificate online with a credit card:
www.gro.gov.uk/gro/content/certificates/

Click on “Order a certificate online now”.

It is cheaper to buy the cert when you can enter the index details [above].
They ask "Is the GRO Index Reference Number known?". Answer: Yes

If you have trouble ordering the cert let me know and I can give you step-by-step instructions. The main one is don't enter anything extra! Some people have entered a second name not given in the index, or an age, and received "not found" in return.

The cert may have no further information than you got from the board, but it should have occupations as well as names for the fathers, and you need to confirm the names to go further back.

Sue