You're getting right along there Mr. Firelock, looks like you are getting into the swing of things again. Two minor points I would like to make: I too use an exacto knife for beginning an inlay, I hold the shaft a further up though, seems to impart more control for me. Maybe give that a try and see how it feels. Also, since you know how thick that tang is and once you have it inlet about 3/32nds just go ahead and hog it out to almost the depth you need. Its quicker. Its kinda like define it and go down a bit then hog the wood out almost to final depth but then ease up and begin using the blacking to refine to the depth and fit. Slow/fast/slow. Your tang inlet looked fine.
Looking forward to your continued progress.
dp