Very nice carbine - W.L.A.C. - Westmoreland and Cumbria (?) a converted Yeomanry Unit - these units were sometimes converted on the fly. Also they were split because the government couldn't order Yeomanry units overseas (they were like reserve units) so the members had to volunteer, the members who went over were "1st units" the ones who stayed home were "2nd units". Westmoreland is frequently seen abbreviated to WL. Just a guess.
I hope the barrel is good, those are very classy carbines.