I couldn't resist to ask owner of that blade about mirror polishing flat part of the blade. It was screaming about it and I decided to give it a go. I thought that I will start from polishing compounds straight away but after 3 mintues I gave up. I must prepare that part for final polishing. The point is that first kanji is hand made and it is not very deep. This is a reason why I am a liitle afraid about removing metal from that part.
Second kanji is stamped and it is quite deep so I don't have to worry about it. Here you can see some original grind scratches which I have to remove before polishing. They doesn't look like but they are very deep.
I have used small DMT diamond plate as a base and wrapped 320 grit sandpaper with felt baking.
Also I've read somewhere that it is good to use glass cleaner instead of water when using sand paper. I've tried it when I was removing low spots on diamonds and it worked well. I gave it a try with sandpaper.
That part of knife is not perfect flat, as someone would say, so I was removing metal from sides. It is little concaved in the middle. Anyway it started to reflexing some light.
I didn't have more time today because of my day time work but I will wake up earlier tommorow just to spend more time on polishing. Once I remove original scratches I will start polishing with compounds. It shouldn't take a lot of time. TBC