A non-streetable bike is no use to me, so, unable to afford it or want it that much (or so I contend), let the description of the sour grapes begin!
Here's a restorer who's completed engine and gearbox rebuilds 10 miles ago in order to sell the bike at top dollar but did not bother coming up with Whitworth (or other British thread) fasteners for a variety of attachments, like the mudguards and the shift lever for example. Then, there is the matter of "STB" on the gearbox. My A10 has an "SC" scrambles box and the other two boxes I have are "STD".
Others will see more subtle issues or, maybe, the great value, but I just don't see $21,000, even as the opening negotiating number.
Richard L.