Thankyou. I've just been looking at an 1891 map and found Lea Bailey Inclosure as the large area East of Mitcheldean (and I suppose the 'formerly detached part' around Knacker's Hole)

Interestingly, there are buildings there called Banner's Cottage and... Knacker's Hole. I have also found an entry on the 1901 Census for George Robins. woodman (a 3xgreat uncle, and oldest son)living at Knacker's Hole, Walford, Herefordshire. I think this is the same place. If so the 'residency' rights must have passed down to him.