You can easily follow D50's racing history by accessing our Formula Race Result database - it's free and full of Serial Number stuff. 12 poles where relating from 89 race entries, followed by 11 victories.
The number of cars produced differ from source to source, however, 10 chassis number are known. It is very likely that none of those have survived, even if some sources say that some museums would have on on display.
It is known that at least 6 to 7 Replicas of the D50 do exist. One of those is D50A-0007R, the car offered by RM in Monaco. This one has been built around an original D50 engine by Guido Rosani of Torino.
Btw., Cartrix produced two "standard" D50 for the use on slot tracks - a red one and a yellow one, more recently Carrera provided the one with the aerodynamic upgardes in limited number.