They made a lot more than a few hundred (in total) during the 1952 and 1953 model years (but it does get down into the hundreds when you dig to specific models each year, in some cases). During 1953, Sears used some of their leftover 1953 models as giveaways in store promotions so they ended up getting spread around the country.
It should be noted that the Sears Roebuck & Co, executive who spearheaded the Allstate project ended up becoming the Chairman of the Board at Sears a year after the project ended!
