Wiltons and Axminsters are probably the easiest to do an insert repair on. Pity you are so far north I am in the south and have done quite a few over the years.
Actually did one last week on a 20 year old Wilton, sparks from the fire had caused a burn hole, just got a piece from a remnant and cut the damaged area out and dropped new piece in. She paid me on a Coutts cheque (Queens Bank).
As the carpet is new it will be much easier to do, the pile will wear as the carpet does and the colours will be a perfect match..
As you said ask around for an experienced fitter, one that does borders on Ax's or Wiltons etc, the older the fitter the more experienced they are, they work for better quality independent shops or John Lewis shops and do better quality work and not just for C@rpetpoope. Jim Neal will say call your local Servicemaster as that is what we used to do a lot of.
There are people who can actually take the tufts out and reweave new ones in, mind you it can take up to a week, seriously, depending on the size.
Actually suprised Wiltons arent interested, Axminsters have a list of people who are trained to do there retufting on site.
Good luck anyway.
Murky