I started rereading the entire series of Parker crime novels by Richard Stark (really Donald E. Westlake). In the last chapter of the first book, The Hunter (1962), I noticed something for the first time:
They went back down the hall, moving faster now, toward the door marked ST LOUIS SALES, INC. The man named Wiss took a chisel from his pocket and held it by the blade end, like a club. He was the only one Parker hadn’t known before; Joe Sheer had recommended him. The other two, Elkins and Wymerpaugh, Parker had worked with in the past.
Wymerpaugh here is one of Parker’s crew on a quick job stealing money from the Outfit.
This is the only time he appears in the series.
Westlake was a great admirer of Anthony Powell and his twelve-novel sequence A Dance to the Music of Time, as I wrote about in 2015 in Westlake and Powell. One of the major characters in the series is named Widmerpool.
Widmerpool is mentioned by name in Plunder Squad (1972)
The air conditioner had been on, but Sternberg switched it off first thing, turned the thermostat up to seventy-three, and opened the window slightly. By the time he’d unpacked and desanitized everything, the air in the room had a bit of life in it. Sternberg stripped to his boxer shorts, turned down the bed, settled himself comfortably with his pillows behind his back, and opened the Anthony Powell novel he’d started on the plane. It was Magnus Donners he wanted to identify with, but he kept finding his sympathies going to Widmerpool.
By 1972 the first ten books of the Dance were out. The sixth, The Kindly Ones, came out in 1962 (same as The Hunter), when Westlake turned 29. I don’t know when he began reading Powell, but it’s reasonable he got on to the Dance early and then read them as they came out. I think he twisted “Widmerpool” into “Wymerpaugh.”
UPDATE (05 January 2022): Wymerpaugh is mentioned in The Handle (1966). Alan Grofield (in his second appearance in a Stark novel) asked him for a recommendation for a man who could drive a boat, and the man he named did not meet requirements. “‘I just asked him for a boatman. Wymerpaugh says try Heenan. He didn’t say anything about all this.’ Grofield sounded not only surprised but also insulted.”