L to R 3rd variation No1 mag, case should be stamped with a 3 that is most likely over a 2, conversion of earlier No1 mags for use with MkVI & VII ammo, auxillary spring should be stamped with a 3 & the follower a 2.'

4th variation No1 mag for use with MkVI & VII ammo, case & auxillary spring stamped with a 4 the follower a 3, both of these mags were fitted to MkIIIs & MkIII*s

No4 mag.