"For ANY fire in-flight, the first thought must be to GET DOWN. Major fires in these old airplanes can cause structural failures in less than 60 seconds (there is film to prove it), and it will take not less than three minutes to get this airplane down to sea level from 9,000 feet or so. If the fire is brought under control, it's easy enough to stop the descent, and then evaluate the options.
With a serious fire on board, DO NOT attempt to "stretch" the flight to some airport that is even a short distance away. Put the airplane down in the water, or anywhere, under control.
Even without fire, water is by far the best bet for an emergency landing. With a fire, you're carrying a major fire to the scene, where fuel tanks are very likely to burst. A water landing can only help."
Outstanding guidance, albeit, second nature to every professional aviator on here (hopefully).
There is an old early CRM video of the Nimrod ditching in the Moray Firth (uncontained engine fire) which depicts this exact scenario perfectly...the skipper (who I knew well) stuck it in the oggin, even though the runway was a few minutes away. Structural analysis later showed that ballsy call saved all onboard. Well played AS.
And as for the document/insurance thing...check out why Damien Hill (the racing driver) grew up poor.