All right, Mr. Picky
Churchill I - 2pdr on turret + 3in How in hull
II - 2 pdr in turret + BESA instead fo 3in How in hull
II CS - 3in How on turret + 2pdr in hull (wow, Mk I in reverse!)
III & IV & IX - 6pdr
IV (NA75) - M3 75mm gun (US)
V & VIII & XI - 95mm How
VI & X - 75mm gun (Vickers)
VII - ditto