Me too @Voyager, a early iron head 2 port 4G Mk1, with sidecar chassis & box chair in my case. It was blowing a bit of oil smoke but seemed to run OK. However it turned out the previous owner hadn't kept on top of maintenance (understatement) , so the engine proved to be way beyond economic repair.
Still what do you expect for a tenner. At least the bike parted out for a handsome profit - kept us lads in beer tokens.