B3/CR 53 GA, the Ministry of Supply part number for the L2A3 submachine gun.  Invented by George Patchett, and perfected for production by Sterling Engineering Company, Ltd.  Once accepted by the Ministry of Defense for general issue as a supplement to the FN rifle in 1956, it became the most refined and rarest Sterling SMG of them all.

Sterling went on to produce about 16,000 of these guns before procurement was cancelled in 1959 in favor of ongoing L2A3 production by a government owned manufacturing facility.  Government production totals reached about 164,000 guns before shutting down in 1960. All this was not without cost. In 1966, Patchett and Sterling were awarded a sum of money for breeching of patent rights. Perhaps most importantly for Sterling, it was granted the right to exclusively market the gun around the world without competition from government supplies. To this end, the far more common MK4 commercial version was born.

We at CPS Co are offering a limited supply of recreated 1958 Sterling L2A3s. The time when the NATO part number first appeared on the magazine housing. Each gun is carefully assembled and finished using the finest of parts and NFA registered Sterling receivers. Certain modifications are made to reflect the era and Ministry of Defence improvements for rugged military duty are also incorporated. Each gun is listed in the National Firearms Registry and Transfer Record as the L2A3 model.