Tim, I have posted a reply on the NOC forum as follows :-
"The Orchard & Madden book is a fantastic piece of research but fortunately some more snippets of information have become available since it was first published in 1995.
The motorcycle numbered W84817 was delivered under contract S2602. Reference to 'O&M' shows 5000 machines with WD Serial numbers C5266965 - C5271964. Ordnance records show that these were in fact W83765 - W88764 (you'll notice that the last two digits match the serial numbers).
W84817 would have displayed the number C5268017 on the fuel tank.
This contract was actually noted for delivery 'Jan 1944 at 1600/month' which would put delivery of yours to RAOC Chilwell somewhere around January or February of 1944 with onward delivery to a unit at some point after this."
By 1944, the WD16H was no longer being issued in great numbers to the British Army but the Canadians remained loyal to them and most of the images of bikes from this contract show them in Canadian service. At the end of the war, most Canadian transport was left in The Netherlands so this may account for the Dutch connection (an examination of the post-war documents relating to it may shed some light) but there is also the posibility that it was bought from post-war BAOR sales or that it moved to The Netherlands more recently (the Dutch are well-known for raiding the UK's diminishing supply of old motorcycles and spare parts 
)
Don't be afraid to get it dirty !
