Air Britain ‘The Squadrons of the Royal Air Force’ has these squadrons based at Oban:
209 Sqn, Stranraers, 7 Oct 39-16 Jul 40
210 Sqn, Sunderlands, 13 Jul 40-28 Feb 42
228 Sqn, Sunderlands, 10 Mar 42-11 Dec 42
240 Sqn, Stranraer, 30 Jul 40-28 Mar 41 (text says Oban, tabular data says Stranraer, which appears to be a typo)
330 Sqn, Catalina, 28 Jan 43-12 Jul 43
524 Sqn, Mariner, 20 Oct 43-7 Dec 43

The first four squadrons also flew the London, although some years before moving to Oban. I suppose the possibility exists, though, that a London propellor might have been some sort of trophy or keepsake that got left behind during yet another move.