I'm no GR expert (my Tornado knowledge is all related to the F3) but would a GR1 be able to get a "radar lock" on a target? Also, what self respecting pilot wouldn't attempt to lock it up if he could (get it on tape in that snazzy little VCR in the back seat - assuming that the GR1 had it).
A GR1 equipped with an EV3 radar could get a radar lock (single target) and a rather crude b-scope display in the back. This could be cued to give a rather laggy display in the HUD ready for air-to-air override mode to be taken from the front.
The rather quaint recording system (HDDR) in the GR1 was a digital display projector projected in front of a bit wet film to capture the head-down display image - if one remembered to set it to run. The front relied on wet film too for the HUD.
ah, F/A, Stab, Baro-IN, HDDR...