Educational board made by ITT LORENZ, SEL STANDARD ELEKTRIK LORENZ / TEL aka ITT Schaub Lorenz. There were at least 2 versions. Version 2 in a plastic suitcase:
Source: https://www.mikrocontroller.net/topic/103926
First version here in wooden suitcase 1975 or 1976
I found the manual of the training course here, 168 pages, German