Good chippies are VERY hard to find and if you do find one they are bloody expensive supposing they can even come. However, a firm is always terribly expensive, so you need an independent bloke. Will ask my "boys" if they know anyone and will PM you.
I know a lovely young man who can do almost anything in building and decorating -- expertly and fast. Good attitude too! He works with a small group of good artisans, so if anyone wants to know more, email me privately and I'll let you know contact phone no for him. (Currently, he's installing a kitchen. Last job was building an extension. He makes bespoke furniture too, but its cost reflects its originality.)
Not sure if you have found someone now but a friend of mine is very good and reliable too - he is based in Sydenham but happy to work in SE1 - his name is Stephen Trickett and his number is 0790 5533789. He was recently recommended in both the Evening Standard Property Section and Time Out's Essential Services guide. He makes bespoke furniture, fitted wardrobes and more or less anything wooden, I think! Well, maybe not boats.
[James - if this counts as advertising, please remove and I will repost with my email address for anyone who wants details]
HI, although it was long time ago, I might recommend you Simon Kid (020.79283624). He did a great job, very similar to what you are looking for, was clean and far cheaper that other quotes I got at that time as well. Only drawback (consequence of his success?), he might not be too fast in coming and doing the job (but if you can wait)