According to Heinz Baumeister's Ben Webster discography, here's what's missing in Stereojack's list:
2may57 - LA - Dave Howard with Benny Carter and his orchestra and the Jud Conlon Singers (RCA-Victor)
dec59 - LA - Ben Webster & Gerry Mulligan in Dinah Shore show (video tape exists)
12-14jan60 - LA - Maxwell Davis: Compositions of Duke Ellington and others (Crown)
10+11may60 LA - Nancy Wilson: Something wonderful (Capitol)
sep60 - LA - Jimmy Rushing & Helen Humes (Columbia)
aug61 - LA - Wynone Carr: Wild wonderful Wynona (Reprise)
2jan62 - LA - Jimmy Witherspoon: Jazz Casual
And a few more live recordings with Jimmy Witherspoon survive, with no exact date.