That Bren in the pic, im guessing is WW2 era or slightly later. There have been many incarnations/modifications of most weapons.
But if u have made a 7.62 mm LMG for the Falklands era, then the general issue magazine at that time would of been slightly curved.
It is is good model by the way
Look forward to seeing how you do the sighting on it, due to it being off to one side.