I might know something about the one in the North East (Barnesbury).
I think they’ve got the postcode wrong unless they’ve built a second BMX track very close to an existing one. Given they’ve called it “Barnesbury” I’m assuming that the post code relates to a correspondence address of Barnesbury CC who did the leg work on it. I only really know about it through friends and racing contacts. The club also host the most popular “Weeknight 10” where I used to be a regular.
I think it is an improvement of the BMX facilities in Gallagher Park as seen in the link below. With directions from where the postcode point you.
https://www.google.com/maps/dir/Gallagher+Park+parking,+opposite+Aldi,+Schalksmuhle+Rd,+Bedlington+NE22+5BP/Horton+Manor,+Front+St,+Blyth+NE24+4SF/@55.1362745,-1.5840056,237m/data=!3m1!1e3!4m14!4m13!1m5!1m1!1s0x487e0d00255755a7:0xc07fcb2aaef2eee8!2m2!1d-1.5840463!2d55.136468!1m5!1m1!1s0x487e72d31993092f:0x24ad21be1d9ea84a!2m2!1d-1.5647318!2d55.1259098!3e0?entry=ttu&g_ep=EgoyMDI0MDkyMi4wIKXMDSoASAFQAw%3D%3D
Here’s some stuff from the contractors
https://www.clarkkentcontractors.com/tracks/regional/bedlington.html
Barnesbury’s website is out of date and their club Facebook page is private. There is one for the BMX and mtb stuff at Gallagher park though. IF you scroll through there is plenty of information.
https://www.facebook.com/BarnesburyBMX
If you want to talk to someone and don’t have much look using their website/facebook page. PM me and I’ll see if I Can put you in contact with the right person.