If you scraped the gib, you altered its thickness, so it will have to be inserted deeper into the slot. And since the taper is pretty shallow it won't take much of a change in thickness to cause problems. From the drawing it appears that the fixed gib is installed with some screws. You may need to put a shim underneath it to get your movable gib back where you want it. Or perhaps were WERE some shims in there that got misplaced?