The British were very careful about stamping this kind of information on the projectiles themselves and you can even see them in the pictures. For example taking the second from the right, you can read "APCBC" which is the type, followed on the second line by "2-Pr" which is the gun and it should be followed by the mark "Mk ..." (it's behind the curve of the shell so I can't read it).
Proper nomenclature should be something along the lines of "Shot, Q.F, Armour-Piercing-Capped-Ballistic-Capped, 2-Pr, Mark I"
Unfortunately I don't have any of the manuals for the QF 2-pr and QF 6-pr, so I can't help you with these, but I'm sure someone else here knows...