https://www.youtube.com/watch?v=jSC5Op53HRA
The description given is as follows:
Steam trains on the Great Western Railway (G.W.R.) Amateur home movie.
Good phantom rides, shots of Brunel's bridge and views from the locomotive on route from Plymouth to Saint Erth.
Locomotives 5934 Kneller Hall class as the 'Cornish Riviera', 6938 Corndean Hall class, 5069, 6837, 6809, 6026, 4548.
Plymouth to Saltash to Truro to St Erth to Plymouth. 4588 (4500 class), 5069 Isambard Kingdom Brunel (Castle class). 5934 (Kneller Hall). 6026 King John (King class), 6809, Burghclere Grange (Grange class). 6837 Forthampton Grange (Grange class). 6938 'Hall' .
A P.S. from Trevor A bit of detective work - I always like to be able to tie down actual dates (don't know if that counts as anoraky).
Having looked through that latest clip, some observations:
The battleship, I can say with some certainty, is the 'Howe' with smaller vessels alongside in what was known as the 'Capital Ships Trot'. I did my navigation training in this area, and in the Sound. Many years ago I saw 'Howe' at these moorings (I always used to look out at the ships from the train without knowing much about what I was looking at) and remember the four big guns on the front turret, a feature of this class of ship. I must have been about 4 or 5, and perhaps my Dad who was ex-Royal Navy, may have pointed her out. Anyway, this sets the 'end date' for the film as 27 May 1958, as I mentioned, when 'Howe' was towed away for scrap.
Moving on to the trains, one was the 'Royal Duchy' with chocolate and cream stock. This coach livery came in during 1956, but the Royal Duchy's first run (from Paddington behind 'King George V' with the headboard as on the film) was on 28 January 1957. Assuming (as it looks) that the film was all taken on one visit, it has to be between these two dates, 28 January '57 and 27 May '58. Note that 6938 'Corndean Hall' (the last loco on the film when the footplate passenger gets off) was still in lined black livery. Earlier in the film, No.6015 and the other 'King' both have the early pattern of double chimney which also puts the film later than the end of 1955. I would guess it was shot sometime in the summer of 1957. So there you are.
If you are quick you'll spot Trerule Box, and also Redruth station.
Also links to other railway films.