I asked for this thread to be reopened because I know of least one other set of numbered volumes, by JP Hawker I have No 1 and 2.
In appearance they are identical to series 2 identified above but Vol 1 is pre '55 and Vol 2 is 55/56 as opposed to 57/58 in series 2 above.
When I requested the thread be re-opened, Graham, the moderator, pointed me to this thread:
https://vintage-radio.net/forum/showthread.php?t=19275
This identifies even more "volume" sets, I don't know how I missed that thread.
Various members have suggested making a spreadsheet to colate all the information. Has anyone ever actually done so?
Peter