I ordered a new pump and it was not the right fit but it had the same type of magnetic motor. The motor on the original pump slipped right off but the new one was enclosed in plastic. So I cut off the motor. Then slipped it on the old housing and it worked!
Then I put the machine back together. A rinse cycle with the new pump showed the repair worked.
Unfortunately water leaked heavily from under the machine. I took off the bottom again and tightened all the new clamps and made sure the original pump was tight. The problem seemed to be the sump assembly. The machine leaked water if I just poured it into the sump area. So I ordered a new sump gasket which was a Danby part but hard to find. Shipping cost more than the part.
In the meantime I put it back together again and tried to run it again. It seemed the leak was better at least. But it would not run. Instead the dreaded flashing 888 indicated something was wrong with the control board. It could just have been a fuse but it could mean more expensive parts with no guarantee it would be fixed.
I gave up and ordered another dishwasher.