Thank you Baz I was looking for sites not divisions with GW in them as EEP was for English Electric Preston.

The net shows EE Guided weapons making the Thunderbird and the Blue Water.

It looks to be a Blue Water tail fin. 

The close up shows the same construction and square attachment as well as angled shape 

https://www.agefotostock.com/age/en/Stock-Images/Rights-Managed/MEV-108…

https://www.agefotostock.com/age/en/Stock-Images/Rights-Managed/MEV-108…

https://www.agefotostock.com/age/en/Stock-Images/Rights-Managed/MEV-108…

http://www.stilltimecollection.co.uk/detail/11843-tpt-transport-truck-l…