Z1OwnersClub GB

Hi guys, I've run across a 1976 Z 650 B1 at a friends house in Chantonnay France, literally in a barn, it's been off the road for years but does run, and needs a good clean, it's all there and is fully standard, he says he's thinking of selling it, does any one know a ball park figure of what it could be worth?

Anywhere between £1k and £5k depending on condition. Need pics to value it.
Why was it taken off the road initially? Did it start on the button or kick? Are the std exhausts on it and good condition or rotted out? Has it got std air box? Euro rear mudguard or short US one?
The questions are endless and until we know we can't give a more accurate value.

Thanks I'll get more info