The Mk.7 was the first Centurion to have the extended rear hull to give the machine a longer range. Initially armed with the 20-pounder, the Mk.7/2 was upgunned with the L7 105 mm gun.
Further modifications produced the Mk.9, 9/1 and 9/2 (uparmoured, Infra-red, ranging gun respectively),
Final mods produced the Mk.12 (Mk.9 with both ranging gun and IR) -
as seen here.
I was lucky enough to be given access by The Ramsdell Collection to a beautiful Mk.12 which some of you may recognise. Many thanks go to Ian Foulkes for organising this for me, and in particular to John Davies.