hi barv,
I was the instigator for the MLRS RRV being built.
I was the Recovery I/C at 39 regt RA workshop when i decided that the M578 was to dangerous to use, and i set the wheels in motion to have it replaced with a new recovery vehicle.
My initial thought was a Warrior ARV (MCV80)however i was told none were available, After a chat with the then WO1 John Sibley (ASM Recovery at DLO)later Capt Sibley he enquired to DLO how to procede.
I retired in 2007 when MLRS RRV was only about 1-1/2 years into its service so i dont have any photos as my mfo box with that info was dammaged and the prototype photo's were lost.
Your best chances of getting new photo's is by contacting 39 regt RA Recovery section in Albemarle Bks, near Harlow Hill Newcastle upon Tyne,
Hope this is of some help.