Phone [Q] Trouble Updating My "Special Snowflake" of a Galaxy Nexus

So right now I'm staring at the bootloader of my phone and trying to figure out how to get it up to Android 4.3... and beginning to wonder if I should just give up and go with some other Android derivative, because this phone is turning out to be a very... special... little snowflake. Here are its stats as follows:

VARIANT: maguro
SIGNING: production

Android Version: 4.2.1
ROM Build Number: JOP40D.I9250ZSMA1

As can be seen in this list, my bootloader doesn't match my baseband version and build, while I can't even spot my build number in the list. If possible, I would like to upgrade this thing to 4.3. My questions are: How does this kind of thing happen? Can I even update it? If so, how should I do this on a Linux box?

Relevant background information:
-> Got the phone in a wonky, broken state for a song. It was stuck on 4.02 and would reboot every 2 minutes. I did some sort of recovery on it with a Windows box, got it hooked up to wifi, and let it update until it was un-broken.
-> When I got it up to 4.2.1, it came up with the language initially set to Chinese, but it has worked for me in English for the past couple months.
-> I'm used to flashing ROMs onto pre-production devices that are set up to make the task easy, and doing it on a Windows box set up for that particular process. I'm new to messing around with the Galaxy Nexus, and I don't want to brick it because it's been a nice phone so far, and I want to keep using it.
-> Be gentle... I'm also fairly new to running Linux on my box at home.