Hi,
Looking at your photos it does seem that you have a WD version, the fuel cap seems to be in the right place for a start! Have a look on the main frame just in front of the tank on the right of the steering column for the frame number, should be just visible. If you cant find it the let me know, I have a photo of where it should be!
As for parts, Hitchcocks Motorcycles (www.hitchcocksmotorcycles.co.uk) here in the UK are amazing for parts, I’ve bought a fair few bits from them to help with the restoration of my flea!
Also Rob (http://www.robvanmeel.nl) is your best source for a manual and parts list in order to be able to search Hitchcocks with the part number!
Hope this is of some help!!
Cheers,
Matt