Pottz, I'm not a hand tool only guy. I just hated how a minor wobble of my powered router ruined a project when I started woodworking. So I just decided to learn hand tool skills so I can understand the woodworking basics and when I need to do detail work, I don't have to rely on my cheap power tools(no money/space for top notch accurate machines) but I can do it with hand tools.
Splinter, thank you for the information! Since the hinge came with polished lacquer on it, I was just worrying it may look bad if I file only one part unless I remove it all the way.
And, it's just a minor thing but please see the picture, you see the gap on the left side. I know no one cares about the tiny gap but I just wanted to avoid this sort of avoidable error. For this hinge, the top side of the marking line is a reference line so if the hinge leaves have the same height, there shouldn't be the gap on the top side (the bottom side was almost flush).