Thanks for the point Andy.
I was a bit surprised as well. After it was established that the car was a 500 cc Formula 3, I tried Googling "images of Formula 3 racing cars" to no avail. So I changed the Google to "images of 500 cc racing cars" and the first listed result was a Flickr pool which had the image I posted on the first page of pictures. Some times one gets lucky, I guess.
As for the participation of the Este in competition, I have no idea except that I am very familiar with the Crosmobile engine. Of course I never heard the name Crosmobile, it was just Crosley to me, but I understand the export model was called Crosmobile to avoid confusing it with Crossley. In any case, I owned a '49 Crosley in 1957 and rebuilt the little engine (before I got bored and replaced it with a '41 Ford 60 hp V8). Actually, the Crosley was a gorgeous little engine (overhead cam driving the valves directly-no pushrods or other intermediate lifters), which, with the addition of a decent carburetor (frequently a side draft Weber), would easily turn 10,000 rpm. The locals in my area (central Illinois) found the Crosley engine to be very competitive when used in Class H sports car racing.