Did any combat aircraft operate from Northolt later than that? No RAuxAF Spitfires or Meteors?
Certainly no Auxies. Post war around the capital there was 600 and 615 at Biggin with Spitfires and then Meteors, 601 with Spitfires, Vampires and Meteors at North Weald; and 604 similarly equipped at Hendon and then North Weald.
I had some hope for our gallant allies ("shut up in Polish!") whose memorial is of course nearby, but the last ones (Spitfire IXs of 317 Sqn) left in April '44, five months before 140's Mossies.
[information from Halley [Sqns of the Royal Air Force] who my friend
Old-Duffer opines is not always reliable....]