At this point the case is looking awfully good, but there's still a lot of places where you can see the edges of the melamine, and probably lots of edges where it peeled at the cut, too. Fixing those will push the case over the edge from looking good and almost done, to looking fantastic and making you feel like it didn't really look that done before.
You'll need to use a lot of masking tape to apply the touch-up paint, but only a tiny bit of actual paint. I recommend removing the controller board entirely during this process. Anywhere you can see the white of the inside of the melamine, paint it black, with one exception: the actual surfaces that you'll be covering with the T-molding. When in doubt, err on the side of painting. Be sure to dab the edges of the wood where the melamine coating peeled or splintered, anywhere you drilled holes and exposed a bit of the wood, and edges that are only seen from the side -- walk around the case and look at it from all angles. The drawer and the hole around it will need a lot of attention here, as will the gaps around the speakers. Expect to do several passes -- what looks thorough at first will only reveal more white spots later once the other bigger white spots are cleared up.
The proper method of applying T-molding is to use a router or Dremel to cut a notch right down the middle of the edges to which it will be applied, then to press it into that groove. Even if you did this, you might want to hot-glue it anyway to keep it in place, particularly around the concave curves around the monitor. Even if you have a router, though, making sure that groove is right in the middle of the edge is very difficult. Jeff McClain, who is a far better carpenter than me, wrote on his Ultimate MAME page (from which I took a lot of ideas for my case design and implementation), that he could never get the router or Dremel to do the job quite right, and in the end, putting up the T-molding was the worst part of the whole project.
So I decided to skip that entirely. Instead, I used a utility knife to trim off the T part of the T-molding in every spot where I put it that there wasn't already a natural gap. (Maybe there's molding that comes like this already, but I wanted to use the T in a few spots, and ensure all my molding was consistent, so I just bought the T-molding and trimmed. It only took a few minutes.) Then I hot-glued it on. Where Jeff spent a whole day doing T-molding, I spent a couple of hours, and it looks just fine.
When the molding is done, the case is done. Clean up your workshop and put away your tools, then relax and enjoy the game!