This looks very much like the german Ostner Rex 4 from the late 1930s.
If it is not the ordinary version, it might also be a ca. 1940 Talbot Elektro-Lieferwagen "Rex" (4,4-8,8 kW power...),
built by "Richard Talbot Spezialfabrik für Elektrofahrzeuge GmbH", Berlin-Friedrichshafen.
It used the before mentioned Ostner as a basis.