So, I still had my work cut out for me.
I made sure I hadn't missed anything while cleaning, used more oil and let it soak. I kept turning it over by hand and sometimes with the motor. It wasn't improving that much.
Okay, time to dig into the motor. I decided first to see if the motor was lubricated. Opened up the area where the grease wicks are located and found hardened grease and wicks that were like rocks.
I carefully removed them from the springs and put new wicks in. Then filled it back up with vaseline.
Tried it again and it was still lugging but it was getting better. So I ran it for a few minutes to get the motor warmed up and the vaseline to melt.
And then she woke up from her quarter century (or more per the previous owner) slumber.
https://vimeo.com/153419383