Единственный немецкий ПП, который Джордан мог носить за переднюю рукоятку стволом вниз, может быть лишь Фольмеровский ЭРМА, разные модели которого имели и диски, и коробчатые магазины, перфорированый кожух, калибры 7.63х25, 9мм Маузер Экспорт и 9х19 Пара, он, кстати, может быть собран таким образом, как описано в книге - приклад ( вместе с цевьем ) легко присоединяется к "forward assembly"...
On the handguard had the VMP1925 as a first European submachine gun a vertical pistol grip, for the first time encountered on American Thompson 1921 submachine gun. This front pistol grip will appear on all subsequent Vollmer submachine guns. For the first time the weapon also utilized new style of a field stripping, the same system as one can later observe on the M.P. 38 and MP 40 guns. On the bottom of the handguard was a vertical screw / pin. After pulling this pin out of the weapon, squeezing the trigger and turning the receiver with magazine well and barrel it was possible to remove the receiver forward, out from the body of the weapon.
http://www.mp40.nl/index.php?page=empThe weapon is field striped by means of a disassembly lever placed in the back strap of trigger guard. Once the disassembly lever is squeezed simultaneously with the trigger, the receiver with bolt can be rotated and removed from the body.