Those times are a good general measuring stick, but same day, same track, I think a 512M would certainly beat a Testarossa by a much larger margin than shown here. Interesting to see that the F50 is only shown as 1 sec quicker than the F40. I've always read that the F50 is much better around a track, although maybe the F40's beastly acceleration helped narrow the gap.
It seems even the factory made the mistake of calling it the "430 Scuderia", as seen on the rear of the vehicle....