This one is on ebay for £10000..1916 WD BSA..It may not even be 1916 with chain drive all the way round...My 1918 Model K still had a rear belt...There is also a lot missing and no work done by the look of it, other than an all over coat of green....Times have changed and prices across the board have dropped a fair way of late (WW2 military bikes being a welcome exception so far).....
Personally I don't see the value in this one unless I'm missing something....Ian

email (option): ian@wright52.plus.com

It seems the chain drive may be correct, there are models earlier than 1918 thus equipped...Ian

email (option): ian@wright52.plus.com

Ian,
Chain drive is a model H , I have a 1915 model H. It cost an extra £4.
Same engine front end etc.
The main difference is the backstay, chainstay. Rear hub is the same however it is fitted with the sprocket rather than the belt rim. Same with the gearbox.

It also has a cush drive rather than just an engine sprocket.