I finally converged on the recommendation I consider best: cream. http://cream.sourceforge.net/ Cream is a facade to vim to make it more-user-friendly ... useful for other family members (I am a Linux geek at work comfortable with vi[m], but I needed something more accessible for my family).
"vim -x yourfile.txt"
It will be saved as encrypted with a passphrase.
You can use vim or cream at this point:
"vim yourfile.txt" or "cream yourfile.txt".
Either one will natively open "yourfile.txt" and prompt for the passphrase and transparently allow edits and re-saving as encrypted. FINALLY the quest has been completed !!!!