Hi Cowley, yes, I agree and I also found what seems to be 'Our Hall' (if 4920) sandwiched between 4MTs but both bunker and smokebox connected as you say. The difficulty is that shunting was almost constant although I'm not sure if locos could end up being 'turned' through shunting around the yards? Maybe someone will know.
From my notes, I also can't tell which locos were adjacent to each other as I didn't exactly record as much as I'd liked.
A question to ask your friend's father would be if the Collett 4000g tender attached at Barry accompanied 4920 to Buckfastleigh as I think it did? Weathering and rust stain/markings on this tender do seem to back up my theory that you have 4920 captured should the tender have stayed with the locomotive.
I'll do some more trawling to see by elimination what other halls showed at this time to render them eliminated or implicated with 4920 (this was oldest Hall at Barry and was therefore the first that I chose to search for which seemed to lend itself to the one in your image)
EDIT : searching against each Hall and 80xxx in Barry gave the following :
Interestingly the only Hall I could find parked with 4MT tanks was 4920 which was surprising.
4979 & 6984 still had a Collett 4000g tender attached in 76/75 respectively whilst 5972 had lost it's Hawksworth tender to the steel works,
5952 seemed to have red oxide paint applied in 1970s
4936 lost it's chimney capping fairly early and 5972 & 5967 the whole chimney. The chimney is not visible in your shot unfortunately.
4953, 7903 and 5967 seemed to have lost their tenders early. (I believe the tender from 5967 is stood unrestored at Didcot to this day being purchased as a spare)
6990's tender staining is different to 'yours' and had white paint where number plate existed.
7927 is interesting as it and Collet tender had been painted green in 1975 with the tender suggesting it had been sold for 4920? A spare maybe?
Searching the other way about against each 4MT 80xxx in Barry shows only 80098 and 80136 in same shot as a Hall and in both cases it's 4920. I couldn't find any other images showing 4MTs and Hall in shot together
https://www.flickr.com/photos/dubde...WH-2aNvFaL-V6YfUd-282S5Eq-7ucjSK-dQFk84-DRH37