Ray Galton and Johnny Speight wrote a pilot called The Tea Ladies, aired 4th January 1979, starring Mollie Sugden, Dandy Nichols and Patricia Hayes.
I have for years wanted to find this pilot on a DVD somewhere. I have bought 2 editions of Galton And Simpson's Comedy Playhouse where it isn't on. I now find that Johnny Speight wrote it with Ray Galton. Surely it must be somewhere?