Has anyone heard of a 68 1/2 production run?

To add to Jims comments on the VIN/sequence #`s. My 68 340 has the code for the year and plant with the sequential number (last 6 digits of the VIN) on the rear of the engine block top lip and corresponding area on the transmission. The numbers thing can be a real pain and I`ll be the first to admit that I use the wrong term for numbers found on our cars all of the time. To help clarify some of the numbers, the sequence # is the first group of numbers on the build sheet followed by the shipping order # and finally the VIN number which combines the codes for the car line, body type, engine, year, plant and a 6 digit sequential number.