I would definitely re-mill the top barrel a little, add the centerband, and before you re-turn the barrel, drop some medium CA in all of the pits, let it set up, apply a few coats of medium CA to bring the surface back up a little and start fresh from there. It'll take a little while, but you'll be glad you did. I've had to do it a few times now. You may still have some small bubbles/pits in there, but you can also apply medium CA and polish it back with sandpaper or the first micromesh pad, add another layer, polish it back until you have a clean surface. It looks like you got a pretty good cast, colors look good. I hope you get to cast more and refine your touch. It looks like it's still a little thick at the cap which is a good thing in this case. You can turn a little deeper, getting the white out of the pits. Once you seal the white spots with CA, they're locked in. Turn it down a bit more before adding any medium CA to get rid of the white stuff in the pits. That's normally swarf caught in the pits and drying. The resin equivalent of sawdust. You can definitely get it looking a lot sharper.