Thanks, @gazumped. All of that makes sense and, in the future, I'll go the local file route as you suggested. I noticed the Note History option but I can't afford to spring for the Premium features at this time.
I do maintain a backup of my Mac using Time Machine but, for some reason, it never occurred to me until now to check my backup drive for a previous version of my notes.
I opened the Evernote database folder as described here:
In the database folder, within my account number's "content" folder, I was able to do a Spotlight search for the note that would have contained the work I had done. Unfortunately, the work doesn't exist in my backup. I had added it all at a time between backups so it was overwritten when I forced a sync with the server from my iPhone.
At least I know I have this as an option in the future of checking that folder, and I might even start initiating a Time Machine backup before I try syncing devices from now on, just as a precaution.