Here is how I discussed it in 2010 :
In the mid-1950s, everything changes for racing cars: engines, bodywork, regulations. It is not enough to be the best driver, they must also have the best machine.
The new rules aim to improve the safety of the races by limiting the volume of engines. Ferrari adapted it perfectly and got a lasting supremacy.
Maserati is also "in the race". In 1956, the range of vehicles of this brand is impressive. For Formula 1, the 250 F (2.5 liters) still looks like a shell on external wheels, but its body has become more elegant.
For endurance racing, Maserati introduced the 200 S (2 liters). It looks much more modern, with bulging fenders that protect the wheels.
The car for sale is a Maserati 200 SI which has an extensive race history and has been driven by Stirling Moss.
We see it in two views (with the number 32) in the article shared in 2010 by Turbo.fr.