After the adoption of the MAT 49 as the standard French military submachine gun, elements of the French security services also adopted it to replace the 7.65mm MAS 38 submachine guns. These included the Paris Police, who developed a special variation of the MAT 49 for their use, designated the MAT 49-54. This model had a fixed wooden stock, a long (365mm / 14.4″) barrel, and a new trigger mechanism with a semiauto trigger and a second full auto trigger with a special block to prevent unintentional use. Unlike the police model MAS 38 SMGs (which were rebuilt from standard guns), the MAT 1954 was produced as a special run by the Tulle arsenal from scratch. Only a few hundred were made.
Thanks to the French Ministry of the Interior for allowing me access to this example to show you!