Thanks for your comments.
In terms of labour time, there were two guys who started work at around 8am and they went home at 7 pm, so they did a good day. I can't say if they removed all they said they would, but my mother said they did seem to be bringing a lot of stuff out of the attic. When she turns her tap on now it runs through the boiler to heat up and so she has permanent hot water (before, the boiler had to be on to heat the water in the tank). Her shower is electric - not sure where the water comes from for that.
I haven't got the plumbers calling card on me, but don't really want to kick anything off as I don't want to upset my mother. Ignorance may be bliss. I think the only thing I can do now is wait and see if it runs OK. Rest assured if there are any problems I will be straight on his case.
My initial concern was that they hadn't installed what they said they would, and by the time my mother noticed it was too late.
She had a couple of other quotes, one from British Gas who wanted to charge her nearly £3,000, which seemed a lot to me.