It is a '72 model & was one of Mark Dicker's bikes that I bought from his estate. It needs work (engine rebuild & I think the tank is rusty inside) but is complete apart from the red vinyl "skirt". It is 10 years now since Mark passed away & I really should get around to sorting it !
They are rare here - I understand there were only around a hundred imported into the UK between '72 & '76. They were hand built by apprentices in the factory training school, apparently. In the UK they were over twice the price of the roadgoing ES250/2. I only ever saw one in a dealers - it was in the window of a shop in Buxton 1977/78ish & was there for quite a while.
The last couple I saw sell on Ebay last year were both largely complete non-runners requiring recomissioning. IIRC (and I can't find the completed listings now) one fetched £6500 & the other £8500.
By all accounts they are rather harsh, both on power delivery & suspension, and somewhat raucous.
IIRC Will who posts on here had one that he rebuilt & sold a few years ago.