My father retired from the RAFVR(T) and kept his substantive rank (it was gazetted so, I checked). he was allowed to wear his uniform on HM Queen's birthday, Battle of Britain day, and Remembrance Sunday.
At his funeral last week, his CO attended (serving ATC squadron CO-dad was a CI) along with two other ATC officers (Flt Lt and Sqd Ldr). I knew neither men personally, but I had contact with his former CO and had encouraged the wearing of Full No1 dress at the funeral (including medals), as my father wanted this.
It was extremely touching to have my fathers coffin (draped in the Union Flag with his Hat and gloves on top) saluted in by fellow officers of the 'branch' he had seved in as both a CI, NCO and Comissioned Officer for well over 30 years. Frankly if this was against the rules I'm sorry, but I think occasions like this far from bringing the ATC into any disrepute, do it the world of good.
For the record, the Wing Commander of the relevant wing was a former cadet of my dad on his squadron, and a junior officer on his squadron before climbing the ranks. He was unable to attend due to being on holiday but he was aware of ll of the plans, and had been in touch with me-I knew him too as I was squadron mascot at the time...