Old Hairy,
Let me add my thanks for taking the time to post your remeniscences. Great stories.
While doing some searching in connection the "What Aerodrome" thread, I came across this documentary about Sunderlands flying on the Berlin Airlift. Some great footage, but better watched with the sound down. A terrible soundtrack, even by the standards of the day:
YouTube - Short Sunderland Flying Boats
Edited to add that I've just noticed that at 1:19 there is a brief glimpse of a civil registration G-AGIA, which GINFO tells me was a Sunderland Mk III, previously ML728. Who was the operator?