In 1951 Vaclav Bobek raced in GDR a couple of times with a Skoda powered car, race number 66. The writing on the car (at least its very lower part) may well be 66 if you take a close look. If it will appear to be what I wrote here, that would make it a Czech car, probably even Skoda works car, since Vaclav Bobek was racing for them, if I recall correctly.