Just wanted to update this thread with some feedback about the guys who sanded and stained my pine floors (http://www.thenaturalfloor.co.uk)
Overall the job is ok, though they were in too much of a hurry and really skipped on doing the stair posts properly. Also, although they advertise filling gaps with wooden slivers I really had to push for them to do it. And that part wasnt done very professionally at all. A quick google search shows how it should be done:
These guys had the nearest thing to a totally professional approach I could find,though they are based in Brighton: http://www.gjpfloorsanding.com/
Overall, quite expensive and a little bit rough on the finer details. Also havent replied to my email about a loose board.
They did the soundproofing to my specifications ok though, and the floors look nice.
Not sure if this is teaching you to suck eggs, in case you have not been around anyone who has sanded their floors before, but it is noisey and messy. So (1) let your neighbous know you are doing this- as it will highly likely p**s them off no end if you do not give them a heads up and if you do it might help stay on the right side of them, and (2) when we did it we sealed off rooms we were not sanding with plastic sheeting so the dust did not penetrate, and it saved days of cleaning afterwards.
I know four years have passed since this post was published. However, there is a floor sanding company based in London which you should consider for your next floor restoration - Great Floor Sanding
They are real professionals and are probably the most affordable floor sanders in London.