Originally posted by vbland:
I would contact one of those internet-based handyman companies that have sprung up recently.
I'm in SW16 and have used one for minor repairs and the service was excellent. They are a good option for this sort of thing. I know that the one I use does sash windows.
I believe that we can't give out direct company names. Try googling on "handyman in SW London" or similar and you'll probably find one

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Or, if you are prepared to leave an e-mail address here, I will send you the contact.