If anybody's interested here's the PRIMEKL01 bootloader, latest version.
It's the same LTE/CDMA leaked version that's floating around, nothing changed as both devices share the same bootloader, as far as I can tell.
It's recommended by Google for those who are on 4.0.3 roms with same XXKK06 radio. I've flashed it running Mike's ARHD 2.1.2 and even though it's not a 4.0.3 rom it's working perfectly.
Inside the zip I've included fastboot for Windows for easy flashing.
Put your phone into fastboot mode and execute the fastboot-windows.bat file.
If you have any problems with it just flash back to the previous version.
Source : http://source.android.com/source/building-devices.html
Galaxy Nexus (GSM/HSPA+):
Android Version Preferred Bootloader Preferred Radio Also possible
4.0.1 (ITL41D) PRIMEKJ10 I9250XXKK1
4.0.2 (ICL53F) PRIMEKK15 I9250XXKK6 All previous versions
4.0.3 (IML74K) PRIMEKL01 I9250XXKK6 All previous versions
Galaxy Nexus (CDMA/LTE):
Android Version Preferred Bootloader Preferred Radio Preferred CDMA Radio Also possible
4.0.1 (ITL41D) PRIMEKJ10 I515.EK02 I515.EK01
4.0.2 (ICL53F) PRIMEKK15 I515.EK02 I515.EK05 All previous versions
4.0.3 (IML74K) PRIMEKL01 I515.EK04 I515.EK06 All previous versions