OGL has build a Phantom or two which he posted in his own blog which I saw at the Scottish Nationals earlier this year I was wondering what the designation is/was for a slightly different version.
More RAF Phantoms.

McDD RF-4E Phantom FR Mk-4. Of 2 squadron RAF, RAF Germany 1978.

McDD F-4E(UK) Phantom FGR-5 of 1435 flight RAF Stanley. Falkland Islands 1986.
What would be a mix of F-4E and F-4M? Would it be an F-4EM an F-4ME or an F-4M2? 
I am thinking of Spey's in the back end and an M61 in the front end. Any reasonable or logical ideas please.
Gondor
I simply referred to them as the F-4E(UK) Phantom FGR-5. As they are bog standard E's with a few extra British specified black boxes ect.
The RF-4E is the Phantom FR-4. Clearly they would cease to be bog standard as the various RAF modifications are implemented through their service lives.
The basic premise is that the Spey toom didnt happen.
The Phantom line up could be as follows.
F-1, F-4J for the Royal Navy
FG-2, F-4C for the RAF
FR-3, RF-4C for the RAF
FR-4, RF-4E for the RAF
FGR-5, F-4E(UK) for the RAF
F-6, F-4S for the Royal Navy (Converted F-1's)
That just leaves me the FG-2 and the F-6 to build