I'd be cautious about ordering their "trews". Proper trews, unlike those shown on their web site, do not have a seam on the outside of the leg. With trews the tartan matches on the inseam, which is why they cost more to tailor than ordinary trousers. Here they are charging more for trousers than trews, which seems to be contrary to my experience.

If you are looking for proper trews, and not "plaid golfing pants", then I'd suggest sticking with Stewart Christie in Edinburgh, or Costello & Son in Ilford, north London.