Couple of obvious issues. The left pane glass is toast on the dryer. Finding another older striped pane glass would be a daunting task. It looks like the washer timer dial/timer knob has been modified. The lid on the washer sags, meaning a combination of the following: Missing rubber bleach inlet tube/missing bumper, or the lid is rusted out where is rests on the rubber bleach tube (common). Or a combination of all of the above. That's just the obvious problems without pulling front/rear covers and dry testing the machines.
These machines are at least 51 years old, so a complete tear down to the bases and full rebuild is an absolute must.
It's glass, but unlike the later glass panels, it's frosted on both sides. Maytag quit using that glass in 1959, so finding a panel would be very difficult. Having a panel cut, frosted, and silk screened(?) would probably be extremely expensive.
Here's a pic of the 641C dryer I gave to redcarpetdrew.
I am in the process of restoring a pink MT gas dryer like this one, I believe I have an extra set of glass panels if someone gets this pair. The pink gas one I have is being converted to electric ignition using parts from a MT big load dryer. Originally Bob of Hollywood and I started on this dryer but I haven't heard from him in over a month so I will probably sell it after I finish it and have some fun using it for a while.
I had a Maytag 906 many moons ago, that had a broken glass. I used a piece of clear Plexiglass, cut it to shape, then painted one side white. Put the painted side inside, it looked pretty good I thought. I wonder if something similar could be done.
Now that I look at it, the one in the boneyard must be glass also, I see the light switches off to one side.