Partaking of a free breakfast last August - breakfast if free in August - I noted a former ACM in the bay window (buying a used car springs to mind) and a former Air Cdre in another corner.
There may be some truth in what Biggus says.
That said, the same weekend, I met a retired officer, I would guess gp capt but equally could have been a flt lt. He had flown Hurricanes at Murmansk. Post-war he was an attache in Moscow - fascinating.
A year or so before I met another in the Running Horse. No idea of his rank but IIRC he served on Wellingtons in the Gulf of Aden - equally fascinating.