There's a rather remote DS connection here in that at least two DS actors (Don Briscoe and Christopher Bernau) appeared in the Broadway production of
Boys in the Band in 1969 (when the original cast were doing the film version). That play was written by Mart Crowley, who wrote this script for an unsold, unaired pilot starring Bette Davis and Mary Wickes. I think Mary Wickes would have been perfect on DS, perhaps as Mrs Johnson's cousin who comes to help out in the kitchen at Collinwood.
https://www.youtube.com/watch?v=Ad2UCnpakMc&t=8sG.