Whats it worth? lawn mower, super old.?

i have a super ride LM22-5678C riding lawn mower , 7 hp, 3 speed sold at gamble-skogm.inc in minneapolis minnesota. Briggs and Straton engine. 7 hp . model on engine is 170702. type 6668-01 . code 6902281. the engine was manufactured in feb. 20.,1969 ..the paint is good, its always been inside , runs good, whats it worth?