Heed My Warnings Above
Again, I don't mean to come across as a Debbie Downer but I don't recommend using these as daily drivers even with a hardcore meticulous Qsd-Dan style restoration process on both units. I've been in a bunch of these machines and know what to expect from them thanks to that good ol' hard knox learning technique called experience. They will stab you in the back and fail as the worst possible time. I also don't recommend using these machines as your first prelude into Maytags. At minimum, find a post '65 washer to learn and make mistakes on before touching the A700. That washer is a different animal from '66+ and a simple slip up will turn it into a 200# paperweight.
Last year of the 642C dryer is 1961 and first year of the A700 is 1961. The chances of both units being 1961 are strong. Do the math, that's 58 years old.
Here's some points to ponder before plugging in either machine, as well as my crystal ball future predictions from experience:
Washer:
Belts are probably original and toast. The motor carriage is probably gummed up, if not locked up, and motor carriage wheels disintegrated (or soon will be). This area needs to be addressed immediately.
Damper pads are parched and badly need lubrication by now. Spinning out just one single load of laundry without lubricating them first has the strong potential of ripping the pads off of the base and gouging the damper. That style damper was discontinued in 1965 so good luck finding a non damaged damper today. Polylube is NOT used on these older pads, it's Maytag transmission oil. Use 80/90 gear lube if you don't have Maytag transmission oil on hand and expect your laundry room to reek of stinky @ss for at least a month. I replace all of these old style damper pads with the newer style pads (you'll need to trim one of the 3 pads for proper spacing) and polylube even if the old style look perfect. The newer style causes less friction, allowing tighter spring tensions without inducing vibrations.
Lower o-ring in the transmission is probably toast, or soon will be, and will dump most of its oil on the floor and all over the bottom half of the base. Run it under these conditions and it'll lock up the lower half of the transmission. Most of the transmissions I've been in at this age are less than half full of oil. Whatever oil left has nearly turned into grease which will cause sluggish operation. The shaft in the upper housing relies on oil for lubrication during the spin cycle. Lack of oil or thick oil won't flow into the oil gallery of the upper trans housing during the spin cycle, causing the upper shaft to bind and destroy the upper sleeve bearings, then lock up.
Expect every hose and seal to systemically fail due to age (stem and boot seal, tub bearing seal, cover to tub housing band seal, pump seal, water valve, water valve to injector hose, tub to pump hose, drain hose, air dome hose). Find a post 1979 sealed pump and install it. Those older pumps like to leak from the top seal, especially if the screws holding it are rusted (most of them are). Short term leaks here will rust out that corner of the base. Watch out for the bleach injection hoses, they won't leak right away but soon will. The original style bleach containers will crack by just looking at them wrong, if it isn't cracked already. Check all clamps, they rust out and lose tension, then cause leaks. A blown tub to pump hose, drain hose, or air dome hose will immediately turn your laundry room into the Niagara Falls. Been there, done that.
Dryer:
Belts are trash and probably have flat spots from sitting in one spot on the pulleys for decades.
All sleeve bearings (including the ones in the motor) are bone dry. Running the dryer can cause immediate damage to these bearings, ESPECIALLY THE BLOWER WHEEL BEARINGS!
The front seal is probably DOA. They like to fall off into the heating element which can cause a fire.
The capacitors on the electronic control board are probably dried and dead. Strong chance the automatic moisture sensing options will not work and you'll be relying on the timed dry portion of the dial, if the timer itself isn't dead.
Keep in mind this is only a handful of the many problems that can occur. Considered yourself warned.