I've had several bikes done at PR finishers in Berkhamsted, Its 30 minutes from Euston and they do a fine job for only a few shillings ....the most I've had to pay is 40 quid for frame and forks and they did an Orange 224 frame and swingarm for 30 last year, it depends on what they have cooking I think.
I know its not in town but if i lived in North London I'd put my frame in the car and bring a xc bike with me for the day, theres some of the most beautiful and enjoyable singletrack (Berkhamsted/Northchurch common and Ashridge) to be had in the S East.
I've used tow other powdercoaters one in Tring the other in Mk, they cahrge me more than double PR and they wernt as good, the one in MK was shocking work and nearly ended in a punch up
I used to fish the canal up there as a kid, lovely place, v. civilized.
I used to fish the canal up there as a kid, lovely place, v. civilized.