Thats a radar guided searchlight unless im much mistaken at 1-19.
Yes it is. Although AA Command was done away with in 1955, quite a few HAA units lived on, at least one until 1960 - I think the SL units were largely merged into combined gun and searchlight regiments from c. 1950. Many TA LAA regiments made it to 1967, some in London. Some searchlights survived the HAA era and were passed from RA to RE and carried on in a different role - lighting for movements/exercises. I recall the only remaining searchlight unit in the Army (TAVR then) because it used to do the lighting for the long defunct Colchester Searchlight Tattoo. It has an interesting history - apparently 71 Engineer still had a couple of searchlights, possibly as late as 2011!