HI,
You say they have offered you it?
Sounds like they would prefer you to have it rather than maintain themselves and they've also seen how well you farm the existing.
Ask them how much they were thinking, sound half interested but not over keen, ask about the up keep (spraying etc) and also about the dodgy fence and you might be surprised at how little they would let it go to you for.
They are the Big estate and with a half reasonable land agent/manager who is dealing with land daily he will know how much more important getting the right tenant onto a piece of land is.
Fingers crossed for you, keep us posted
