What year did C-Man change the part numbers on their 3/4" drive sockets? An example being a 1" =v= socket with # 47543 and later # 47773. The latest listing I have for the 47543 is 1972 and the earliest listing for the 47773 is 1987. The one I purchased in 1985-86 was 47773 but I'm missing the 1973 thru 1986 catalogs.