Hey, here are a few suggestions for expanding the British tech tree flavour (Thus adding a bit more)

Light Armour:
FV301 (FV304 SPG and FV305 TD)
FV401 (FV404 SPG and FV405 TD)
Scorpion
Scimitar

MBT
Centurion Mk 7/2 (Conway TD)
Chieftain (Chieftain Sabre SPAAG)
Cheiftain Mk X ('JagdChieftain' TD)
Challenger I

Super Heavy
Conqueror (FV215b TD, Conqueror Gun Carrier Experiment SPG, This is not strictly a Super Heavy but we didn't really invest in that by then)

Anti Tank
QF 32 Pdr (This did exist in a mobile infantry division but only saw testing)
BAT Recoiless Rifle
WOMBAT Recoiless Rifle

Infantry Anti Tank
MOBAT Recoiless Rifle

Modern Anti Air
Green Mace

Jet Fighter
English Electric Lightning
CAC Sabre (More suitable for Canada, Australia and New Zealand)
de Havilland Venom

Sea Jet Fighter
de Havilland Sea Venom
de Havilland Sea Vampire
Sea Meteor

Jet Bomber
Bucaneer (Strictly a Sea based naval bomber but later used by RAF)

Mechanised
FV300
Warrior

This is all I can think of off the top of my head that are around the timeline.