I successfully revitalized a Windows 7 computer,
loaded Evernote_6.25.3.9348.exe
copied Legacy data files there,
and ran the upgrade.
The upgrade wanted to sync with the mother ship, but I did not provide a password to Evernote. It re-asked half dozen times. There was one Evernote which reported it was unable to download something, so I deleted that note.
I disconnected Win 7 pc from internet. Win 7 machine is still connected to internal network (and printer). See https://answers.microsoft.com/en-us/insider/forum/all/how-to-disconnect-pc-from-internet-but-retain-lan/4eca25dc-e98c-46a6-af4d-ab50e3847551 . I used option 2.
I had had trouble getting the .exb file to the Win 7 box. After a couple attempts, I ran out to a computer store and bought a 1TB SSD drive which copied my data file correctly in minutes!
As far as I can tell, Evernote Legacy is all working fine. There is a red exclamation point on the Sync button.
I am running Evernote 10.79.3 on Windows 10 Desktop.
TdeV's post in Is it possible to keep Evernote v6 (Legacy) programs on Windows computer? was marked as the answer