Maybe, but probably not. Schuster's info on the historic Group C / GTP site says this is the ex Speedy, Bergermann JM19, i.e chassis 124,
http://www.groupc-gtpracing.com/cara...cschusterm.htm
Photo on racingsportscars during it's Interserie career:
http://www.racingsportscars.com/phot...05i-photo.html