Leitz Leica VEHIG Ground Glass Housing

very rare ground glass housing complete with 5x slide-in magnifier, with special arm to be mounted on Leitz stands (STARE for example) - the arm is very similar to the one included in the STARE copying outfit but slightly different to be able to mount the VEHIG housing in the correct place - please see various illustrations and detailed descriptions in LEICA HISTORICA VIDOM 86 pages 35-47 & Wilhelm Albert Geburstage der Leitz Foto Konstruktionen ab 1927 page 33