This can only be 101 or 102, probably 102, the first early cars seem not to of had perforated radius rod tunnels (although I stand to be corrected) like 103 and 104 and the horsecollar is of fabricated construction.
I seem to remember OVX 355D was the first car to run a ZF trans and was tested throughout europe by John Horsman and the then FAV works superintendant and chased across borders by customs during those tests. cant remember chassis number though. correct me if I am wrong.