EGNM: I have only ever seen 2 MET choppers at Fairoaks. The ones based here are the South Eastern Police air Support Unit. They cover London, Surrey and Sussex.
The two that are here are Registrered G-SEPA and G-SEPB.
The two in the pic the LGWboy shows: G-METD, is now G-SEPB, and G-METC, is no longer at Fairoaks. I am unsure as to what Happen to this aircraft?
Sorry I can’t be of more help to you.