Serial numbers can be confusing. There have been 3 separate companies make Mark V's (Magna Corp, Yuba, and Shopsmith.) There have been manufacturing facilities in several cities (mainly Ohio) over the years as well. When SS took over the rights from the defunct Yuba company, several years had passed and records were sketchy.


Some clues to the age of your machine
1953-1962 machines were 2 tone green (greenies)
early greenies had no inspection port access hole nor cutouts to see the gilmer belt. These were incorporated bit by bit over the first few years.
1962 Anniversary models were 2 tone brown (brownies)
That year they switched from gilmer to poly v drive and changed the motor from 3/4 hp to 1-1/8 hp. You may find a 1962 machine configured either way.
From 1963 on they have been gray. They have used several shades/textures over the years.
1985 changed to 2 bearing quill
Mid 1991 they went to the type C headstock casting with a larger inspection port opening and cover.
1993 or so they started using the red safety switch and changed the location of the switch.