Cartoon on a postcard, first published in 1981:
Cartoons to download: toons.to/annielawson
This is the full range held by Cartoonstock who provide them for publication, or made into prints and other products.
If you don't see the one you're looking for email email@example.com or you can buy a pack of 20 assorted cards from: annielawson.bigcartel.com/
requesting the ones you want, and I'll see if they are available.