250 acres is a small farm these days. Those old tractors can keep running on small farms for many more years if you care for them. Though upgrading to a newer used tractor may be worth it for the the greater fuel efficiency (you didn't say, but I'm guessing those are gasoline tractors, diesel was just starting to come out in that era)
Jeremy Clarkson is a multi-millionaire global celebrity, him investing maybe 5% of his money to own a bigger estate than most actual farmers is not a surprise.
