It's out! I had to resort to cutting the head off, lovering the subframe down a bit and then it slide out to the side no problem. Not seized in the car at all but the bolt is well and truly seized in the bush. All the penetrating fluid hadn't touch it as it still looks bone dry.
The bush is so far undamaged so I'm still only down one bolt. I'll worry about the bush later but it will be a lot easier with it off the car.
That's all for a few days.
Merry Christmas to anyone reading, and again, thanks for the advice and encouragement.