Will try. Have just deleted the evernote app again.
Location for file is User/Library/Application Support and there appear to be two applicable plists: com.evernote.Evernote and com.evernote.EvernoteHelper
Also in User/Library/CoreDate there is com.evernote.Evernote
Also in User/Library/Group Containers is a bunch of Evernote stuff
There is other more specific stuff regarding web browser extensions and iphone backup stuff which I'm leaving well alone.
Have moved the rest of the files above to test......
BINGO!
Logged back in and it's working and notes are restored.
Evernote helper file has not yet been recreated, or ExternalRecords, so I will keep hold of these files for now, just in case I need to replace them, but I somehow doubt they will never be needed, as they should just get recreated as and when they are needed.
Success (for now)!
Thanks for your help gazumped!