Mac tools was originally called Mechanics Tools and Forge until the 1960s changed to Mac tools.There were 3 parts of Mac tools,Mac Allied Tools Corperation,Mac Tools Inc and The Clinton Tool Company.The Clinton Tool Company merged with Mac Tools inc in the 1960s.Mac Allied Tools Corperation aka Matco was with Mac 1946 to 1979 and the split happened in 1979.I do have a complete Mac flare nut wrench set from the 1960s that has no gaurentee stamped on them,must had no warranty on them back then.A former Vetronix rep my dad knows has the Dale Earnhardt Sr. edition Mac tools,all of them and know they are worth money now since his death in 2001.