The only true DC3s were those built pre-war.
The likely candidates are, as described above, the Swissair ones, which carried on throughout and actually well into the 1950s, and the KLM fleet. Most of the latter was lost in various ways in WW2 but a couple which had been in the UK survived to be handed back to KLM afterwards.
The real issue is whether they actually came to Croydon once civil flying restarted in 1946, when European operations restarted they were generally at Northolt, and long distance ones the first Heathrow users. They may of course have come on government service, which actually accounted for muchmediate post-war flying.