Re: correcting problem with door hinge mortise
If you have finished installing the hinge and it's flat and level with the door, I would say you have a couple of choices. You can neatly remove the rest of that little strip of wood and glue a new piece in, sand and finish or you could use wood filler to build up the missing area, sand and finish.
By the way I would mask the hinge while doing the work which ever way you go.
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