Thanks to the tenacity, curiosity and contacts of John Freeman - writer, editor, creative consultant, publisher and compiler of news site ‘downthetubes.net.’ - the puzzle of the Triffid strip has been resolved.
Paul Dawson identified the VISA 3 label on the back of the artwork as relating to Oxford University Press – Educational Division and their publication of workbooks for students of English.
Andy James found the very book so thank him for the pictures.
I never drew the entire ‘Day of the Triffids’ story just the two pages under the guidance of a writer who was it seems influenced by seeing a BBC version of the tale.
John ‘s fuller version of the search is at - https://downthetubes.net/?p=124477
where he also details other comic book versions of The Day of Triffids.
Thanks to all for the detective work,
The workbook featuring Sean Connery is a 2002 edition.
All copyrights acknowledged.