I believe that the Tail Lights Lens on the 1951 Ford Country Squire were glass, the same lens as used in the 1933 thru 1936 Fords. In Australia, the same taillights were used on our local 1937 Fords. However, on the passenger cars with the new fancy tail light, the lens was plastic. From my observation, the 1951 Ford passenger cars used plastic tail light lens for the very first time, while the wagons continued using the carry-over early glass lens. I have a NOS Ford lens for the 1949 and 1950 Ford passenger car, and it is glass. Please correct me if I am wrong?