Graham, that tidbit came from a 1968 Electronics World article about the introduction of D-Jetronic on the VW Type 3. The article was written by:
Fred W. Holder / Technical Supervisor, Bendix Field Engineering Corp.
The patents that covered the D-Jet were obtained by Bosch from Bendix. The D-Jet ECU was a much improved version of the original ECU designed for the Bendix Electro-Jector. That original ECU contained vacuum tubes! First application was 1959-1960 (?) Chrysler B-block engines. Eventually all were recalled and converted to carburetors.