Comparing these two lists:
www.lostshows.com/default.aspx?programme=ff3578ef-0c2a-482a-8c42-e2b95992bc96www.imdb.com/title/tt0861749/episodesSuggests that the following episodes survive:
From the first 2 series, all written by Galton & Simpson:
05/01/1962: The Offer [Pilot for "Steptoe & Son"]
01/03/1963: Our Man in Moscow
08/03/1963: And Here, All the Way From...
29/03/1963: Impasse
05/04/1963: A Clerical Error
12/04/1963: The Handyman
From the rest of the run (series 3 onwards):
28/12/1963: The Bed [Pilot for "Meet the Wife"]
03/01/1964: The Mate Market
17/05/1966: The Bishop Rides Again [Pilot for "All Gas And Gaiters"]
30/06/1967: The Old Campaigner
07/06/1968: B-and-B
17/09/1969: Up Pompeii! [Pilot]
25/03/1970: Last Tribute (16mm)
28/01/1972: Born Every Minute
27/03/1972: The Dirtiest Soldier in the World
30/08/1972: No Peace on the Western Front
07/09/1972: Weren't You Marcia Honeywell?
08/09/1972: Are You Being Served? (16mm) [Pilot]
04/01/1973: Of Funerals and Fish [Pilot for "Last of the Summer Wine"]
11/01/1973: The Rescue (16mm)
18/01/1973: Elementary My Dear Watson
25/01/1973: The Birthday
08/02/1973: Home from Home (16mm)
16/01/1974: No Strings
07/05/1974: Happy Ever After [Pilot]
21/05/1974: The Big Job [Pilot for "Mr. Big"]
25/06/1974: Pygmalion Smith
09/07/1975: Going, Going, Gone... Free?