Since asking for assistance Evernote has updated, I won't say by itself - but without any intervention by myself. I had fully completed the upgade procedure probably three times in the days before and had been confident of success until the arrival of more identical update notifications from Evernote arrived.
Evernote help is displaying the latest version now, unfortunate because I can't easily delve into Wi 10 to see to find the the location of executable of the older version of Evernote now that it is no longer current.
Thanks for your interest and help.
Help shows: 188.8.131.5281 (307881) Public (CE Build ce-53.2.6641)
I HAVE Updated a few times, Apps in Win 10 Settings displays latest Evernote 6.17.6. BUT, I keep receiving the same Update Reminder Message in Evernote telling me I have 6.15.3 307881.