Hi
How about these few
Abridge Armoury Silver St, Abridge, Romford RM4 1YA
http://www.claypigeonshoot.co.uk/ Three grounds in Essex the main being Cannons Lane, Fyfield,
Fennes Clay ground https://www.fennesclays.co.uk/ includes a second branch of http://www.essexgun.com/
http://www.dartfordclayshootingclub.com/
http://practicalsportingsupplies.co.uk/acatalog/More_Info.html
Regards Hpmark