Sandra,
That was an interesting read. However I rather think that the story is made up of a few facts with much embellishment.
I don't have a great deal of time to spare at the moment but I would make the following points,
"Their traditional history is, that their fathers were compelled by famine, after the loss of their great vessel, to travel towards the rising sun, carrying with them as much of the stores as they could...."
Wouldn't records of such a vessel be available from "VOC" - they have records of all ships that they operated.
For anyone to traverse the thousands of kilometers suggested and through such inhospitable country as the great sandy dessert would be a feat in itself without even considering the many tons of stores that they must have taken.
"I saw below me at the distance of about three or four miles, a low and level country, laid out as it were in plantations, with straight rows of trees, through which a broad sheet of smooth water extended in nearly a direct line from east to west, as far as the eye could reach to the westward,"
Such copious amounts of water aren't feasable in this area
"And what fixed me to the spot with indescribable sensations of rapture and admiration was the number of small boats or canoes with one or two persons in each gliding along the narrow channels [sic] between the islands in every direction, some of which appeared to be fishing or drawing nets."
"about three hundred; that they lived in houses enclosed all together within a great wall "
Yet with such a community there seems to be nothing remaining apart from this one mans account - either physically or verbally to show that they ever existed. It is also noted that this is an acount about a "secret" british mission of which there appears to be no record.
Now having said all that I do believe that there is compelling evidence that there have been some Dutch influence in the interior, but I personally doubt that there would be anything like this.
Denn