Not getting at you, Gasp0de, honest, but you've missed out some of the steps in the Grange Farm/Estate Saga.
The owners of "The Estate" under its various names have always played quite a large part in the programme; they have never been faceless landlords. (And the Grundys didn't actually exist on air until Joe first spoke in April 1970, opening and complaining about the injustice of a letter demanding the rent he had not paid for past quarter...)
At the beginning of the programme, in 1951, the Ambridge Estate of rather over 4,000 acres was owned by Squire Lawson-Hope. On his death in 1954 it was divided up slightly; that was when the tenant farmers were offered the chance to buy their farms and Dan Archer bought Brookfield, while the shiftless George Grundy didn't have the means to buy Grange Farm. Most of the land (what was not sold to its tenants like Brookfield) was sold to George Fairbrother.
Fairbrother left the village in 1959 (having been there since 1951) and he sold his land to Charles Grenville, who ran the Estate firmly and efficiently until he was in a car-crash in 1963 which killed his passenger (John Tregorran's wife Janet) and crushed one of his legs so badly that it had to be amputated. He went away to America, selling his Ambridge property (all but the house and garden) to Ralph Bellamy. It then became The Bellamy Estate.
When Charles Grenville died in 1965 he left house, garden, an annuity and his interest in three prosperous companies to his wife Carol, who later married his friend John Tregorran, but that belongs in parentheses because she had no hand in the disposition of the Estate.
In 1975, fifty-year-old Ralph Bellamy decided to leave Ambridge for Guernsey with his wife Lilian because he had a bad heart and was advised by medics to retire, and sold a bit more than two-thirds of the Estate: 1,500 acres to Brain Aldridge, and 1,000 acres to someone called Mr Barnet, who set up the Blossom Hill Estate. (Neither the Blossom Hill Estate nor Mr Barnet seems ever to have been mentioned again, so that bit of land in the middle of Ambridge can be ignored.) Ralph hung onto the Dower House and 1,000 acres, which he renamed The Berrow Estate.
After Ralph's death in 1980 Lilian inherited the Estate and became among other things her mother's and her brother's landlord (Peggy in Blossom Hill Cottage and Tony in Bridge Farm). She sold the land (apart from the Dower House, and also Blossom Hill Cottage, which latter she sold to Usha Gupta the following year) in 1990 to one Cameron Fraser, who turned out to be a crook: he embezzled money from all and sundry and ran off leaving Elizabeth pregnant. The Estate was taken into receivership and then bought by Guy Pemberton.
Guy married Caroline Bone, and when he died the following year (far too young; he was only 65) he left his property – apart from the Dower House and his share of The Bull, which went to Caroline – to his son Simon, who also turned out to be a villain: he hit Shula more than once and beat up Debbie. Because she was dilatory about persecuting the Grundys (ie failed to force them not to hold car boot sales in their yard) he had also got Shula removed from her job as Estate Agent and replaced with Graham Ryder, which explains her rather wry comment about having worked with Ryder decades ago. Simon tried unsuccessfully to evict the Grundys, which although entirely justified by their behaviour was obviously villainous in the context of the programme, and, after being taken to court by Debbie and become loathed by all in the village, ended up selling the Berrow Estate to Borchester Land in 1997.
BL finally managed to get rid of the Grundys in 2000, when Joe lost his assured tenancy by being declared bankrupt after not paying the feed bills from Borchester Mills as well as not paying the rent and running unlawful businesses on the farm and all the rest of his shenanigans. Brian was not told that this was about to be done, but Joe being Joe Brian was blamed for the entire mess by the old scrote.
BL sold Grange Farm and fifty acres of land to Oliver Sterling.