According to Seventy Years of Buick by George Dammann: "Appearing for the last year was the Super Tourback Sedan, Model 51...Priced at $2,256 and weighing 3,755 pounds, this car has a run of an even 10,000." - Page 228 "Buick's most popular car this year was the Super Riviera Sedan, Model 52, of which 92,886 were built. It cost $2,437 and weighed 3,845. The car used a 125.5-inch wheelbase, as compared with the regular Super wheelbase of 121.5 inches, and was 210.2 inches overall." - Page 227 Note - Buick didn't build a true 4-door hardtop without the "B" pillar until 1955. Any reference to a four door "hardtop" prior to 1955 refers to a standard four door sedan with a "B" post.