How did you go on with this? I hammered mine back. The amounts of clearance & how little movement you get when hammering (and mine was a big hammer!) means that you probably dont want to put the liner back in that area. As long as it is smooth it shouldnt be a problem as you are only ever going to have full lock on at very low speeds. If it becomes a big problem at mot time, i didnt suggest it, but you just use the donor car wheels.
This is what I have had to do with my 308 and picky mot testers in the past.
If yours has already been welded in that area then I would say it is someone trying to gain more clearance rather than wearing through, so not sure how much more you will gain. If it is the same as mine, the bit you need to gain the movement on is right where the structure comes in behind the metal so take care if doing any more cutting.