51 and 52. 1960s production.

Even though new items were being introduced and the Vickers was soon to disappear, some items clearly had to be replaced and the 1960s saw the manufacture of new slide rules with nylon string (51) and even new aiming lamps (52), which would go on to serve with the Sustained Fire role for the L7 General Purpose Machine Gun, as the FN MAG 58 became known.