Then little by little, I dropped the cutter and went along the same cut, stopping an inch from where I cut last. Eventually I ended up with a staggered cut you see
Once I got the steps, I went back with a chisel to take off chunks. I found that scraping it perpendicular was safer that attacking at an angle which tended to take deeper chunks than I wanted to. Then in I went with 100 grit sandpaper to smooth it out. It's not quite as perfect as a CNC would do, but I must say it's not bad at all!