The original idea of Schwinn bike engineering was to keep it simple. Any task could be accomplished with a 1/2" wrench, flathead screwdrive, and large adjustable wrench for crank and headset locknuts. The one piece Ashtabula cranks are the simplist of crank BB design and require no specialty tools.

I think the only metric nuts on a Varsity will be for the Weinmann brakes, 8,9,10mm. Seatclamp and stem/handlebar adjustment will be 1/2". Pedals are 1/2". Super Sport will be the same except for the stem bolts which are 12mm.

Both your bikes will have 5 speed freewheels that most likely are Atom/Millard and require a splined design freewheel remover... Combined with adjustabke wrench or pipe wrench will unscrew counterclockwise.