Salad - At the time (1972 or 73?) I wasn't given the name of the actual unit - just shown what was a very large piece of kit in the R1 at Boscombe. For obvious reasons we couldn't photograph it but we did have a 30-45 minute discussion on fitting, reliability and use. I'm pretty sure we were told it was at least a double unit
A Carousel would certainly be the answer. I saw commercial ones later but they didn't seem as bulky
The Falklands Vulcan had a triple installation "borrowed" from BA I think - but that may have been a later, smaller unit
If you Google "delco carousel" there are some interesting links - unfortunately most of the pictures are of the control & display unit not the actual gubbins down the back.