Well, there's another mystery solved, regarding
author George Crabbe.

"Guide to Britten,"    the affectionate overview of Benjamin Britten
by Michael Flanders and Donald Swann
(premiered in their revue, "Airs on a Shoestring"),

name-checks "PE-TER GRIMES!"
with Max Adrian adding, in an aside,
"Cribbed from Crabbe!"

So now I find out what that means.