The three quotes have finally arrived :dance:

£417 + VAT, £536 no VAT, £1413 + VAT. (I can get the VAT back so that doesn't count).

The £417 does involve finding some outdated 30 Amp breaker to fit the outdated wall panel. It seems to be available on fleabay at around the £15 to £20 mark so this is still the cheapest option. He's dropping by on Monday to make sure we get the right one.
I'm getting all excited wondering what will happen when I plug t'bugger in