If the hammer needs to move sideways, away from or toward the barrel "messing with the inleting" isn't difficult to do.
The thing to keep in mind is that a very small change to the depth of the locating faces down in the mortice will make a rather large change to the sideways position of the hammer.
If the hammer is too far out, away from the barrel, using a small knife to scrape the upper lock locating face surface (away from the hammer) will often remove some of the stock finish on that surface.
Doing this will allow the upper edge of the lockplate to move closer to the barrel.
As it does so, the hammer will move towards the barrel. That is often enough to fix the problem.
If the hammer is too close to the barrel, scraping the lower (towards the trigger)lock locating face will allow the lower part of the lockplate to move inward towards the center of the stock. The lockplate will pivot about the upper locating surface which will move the hammer outward, away from the barrel.