No matter where you live in North West London, be it Camden, Somers Town, Cricklewood, Willesden, Hendon or Golders Green, you can find a local plumber. You just need to know where to look.
Local papers are a good place to start because most North West London plumbing firms still advertise in this way. However, you could also try asking friends and family who live locally if there is anyone they can recommend. If you notice a neighbour having work done, make a note of the plumbers contact details and try to ask your neighbour how they got on with them. That way should you need a plumber at a later date, you will have a list of Camden based plumbers to hand.