Blue is 1954 (Z-3) & Red 1958 (D-2). 54 Super Speed (Z-3 and Z-4) were sold only in the Blue TV Special case the last 6 months of 1954 then production ended. In late 1954 the (1950's style) "Flair Tip" Super Speed model was also introduced. The 54 Blue cased complete set is rare.
