This cut-down Beretta Model 38/44 submachine gun was made by the EOKA (Ethniki Organosis Kyprion Agoniston) terrorist group, which fought in the late 1950s for Cyprus to be reunified with Greece, instead of being a British colony. It shows a clever use of a Bren gun barrel handle as a front grip, usable in the vertical position of locked back to be more concealable.
Many thanks to the Royal Armouries for allowing me to film this unique artifact! The NFC collection there – perhaps the best military small arms collection in Western Europe – is available by appointment to researchers. However, you can browse the various Armouries collections online.