When looking at some pictures from the Zoltan Glass collection on the internet, I found this one:
It claims to be Renato Balestrero. I am not yet convinced.
It also claims to be the Libyan GP in 1935, which might be correct.
Renato Balestrero was racing at that race, with number 34, but that car was an Alfa Monza. The car in the picture most definitely is not.
The car looks suspiciously like an Auto Union. They carried numbers 24 (Varzi) and 48 (Stuck) that day.
The man in the picture looks to be neither Varzi nor Stuck. I haven't found a picture of Balestrero, so I can't tell if he looks like this.
It could well be that the name was taken from nr. 34 on the list of competitors that day.
Varzi's car that race had won the Tunis Grand Prix a week before, wearing number 34, so quite possibly it is the car as it arrived in Lybia, before the starting numbers were changed.
However, the car as seen in Tunis (only one car present there) had an extra air inlet in front of the aero screen. No trace of that in this picture.
Leaves the questions of who is this man in an Auto Union and is the date correct.