Andy- I'll have to defer to the experts, refinishing is NOT something I've attempted, and sorry to hear the finish is that bad...
It's livable, just noticeably different than the upper.Also, the upper came with the forward assist and dust cover already installed. I hadn't expected that.
Yeeeeeessss!Ceracoating is at the top of the stack, but unless you want to buy all the equipment to do it yourself you have to send it off to have it done somewhere. The finish is supposed to be permanent and very durable. You can Duracoat it yourself if you have an airbrush, or you can get it in a can; I've never gone this route but I read good things. What I went with is Alumahyde II from Brownell's. It's inexpensive and comes in a can. It can be scratched off without too much difficulty, but it's much more durable than Krylon. From using it, I learned to not touch the finished product at all until it dries for about a week. When I use Alumahyde for the lower, I taped off the top, the mag well, the threads where the buffer tube goes, and then all the little holes. Blue painters tape is the best for this. Then I run a piece of wire or something through one of the holes so it can be hung up in the sun. I let it warm in the sun for about fifteen minutes, and then apply three moderate to heavy coats, letting each coat dry about five minutes before the next. Lastly I hang the part up inside for a week before I remove the tape or handle it.
As usual CTone, you are fount of knowledge on this subject. I'll look into Alumahyde II.
Once you get it layered and lathered in Ninja-riffic add-on doo-dads, lights and handles and sling-points and lasers, it will be fine and no one will notice because none of those things match-finish either.