Repair is done!!!
The new seal is installed!
I took pictures of the various steps, they are below in their own posts.
Larry's suggestion of using the square end of a socket wrench extension on the square pulley bolt worked great.
I used a pulley/flywheel puller to remove the pulley, as it was stuck to the shaft (probably never removed in its 63 years of existence).
After the clip was removed, the first washer and the spring washer practically fell off.
The second washer, however, was stuck to the seal. Gently tapping at it with a screwdriver and small mallet (one of those craft mallets that can barely drive a nail, let alone damage metal) loosened it.
The old seal was pried out using two small screwdrivers, one on one side, one on the other to bend it enough to grab it.
There is a washer behind the seal. Leave it in.
The unit will not leak oil with the seal removed.
The new seal (part number 15339-DS, what Phil has on eBay) is thicker than the original.
In fact, it replaces the clip, the first washer, the spring washer, and the second washer.
None of the parts that are removed are put back, except the pulley, belt, and the new seal.
Before installing the new seal, I wiped the oil and rubber fragments out of the power unit.
The new seal fits tightly in the power unit. You will not be able to install it completely by hand.
To install it, apply pressure with a deep socket that fits over the worm shaft, and lines up with the seal. I gently tapped the socket with the mallet until it was firmly seated.
When the seal will go no further (out-facing side should be a few mm into the power unit), clean and lubricate the worm shaft and pulley (makes it easier to remove the pulley in the future)
Replace the pulley and belt.
You are done. Enjoy your newly repaired Maytag!