I'll tell you what mate, if you can point to evidence of the specific ancestor of his that was disposed from Hampstead Heath and when that happened I'll concede the point.

Otherwise this just looks like an individual trying to take something from public ownership into private ownership on the sly. Like a land owner trying to fence off a public footpath.

Sorry, but a last name and an accent isn't enough to shift any burden of proof, mate. My last name is English, but my ancestors have lived in the US for 400 years.