Thank you Fitzcarraldo!
I successfully installed a2ps (equo install a2ps --ask). I rebooted as instructed and re-opened my LibreOffice document. I opened the print dialog screen and 'clicked' print. SUCCESS! .....
The Brother MFC-490CW (wireless printer) turned on and printed my document.
The app.'a2ps' is new to me. I'm not sure how it interacts with Sabayon 6. I'll have to look into it.