Like David Tennant, Martin Compston is a Scot who had to adopt an English accent for his biggest television role.

Pardon the football talk here, but the best way to hear an actor's most natural "home town" accent is to hear him being interviewed by a person from the same area he's from, for a show intended to be broadcast locally, and preferably discussing a topic that's personal to the actor.

https://www.youtube.com/watch?v=WibpmErbPhw