I get out all my old tapes and play the Hallowe'en-themed ones leading up to this greatest of holidays. Last night I played that grand old Thriller classic, "The Grim Reaper." I have long wanted to read the Harold Lawlor short story on which it was based, but have had no luck in finding it. Does anyone reading this know where this story might be in print?

No, but you might ask here: http://forums.abebooks.com/abecom/start/ and at rec.arts.sf.written at Google Groups.

Done a little digging. Turns out the story was originally published under the title "The Black Madonna" in Weird Tales magazine, May 1947 (info here. The Internet Speculative Fiction Database, a usually reliable (but not infallible) source does not give any indication of the story being published anywhere other than Weird Tales.

Coincidentally, the blog "A Thriller a Day" - which is slowly working through the entire collection of the Karloff TV series - today features exactly this episode! Read it here.

Thank you all so much for this info. Wish I had a copy of the Reaper painting to hang on my wall! And Happy Hallowe'en to all if we don't speak again 'till then--