Two different VX-31 liveries for the AV-8B. One is jet 81, a standard grey livery with VX-31 markings. The other is Jet 88, the oldest original AV-8B R+ still flying. Jet 88 was a part of the Navy's Biofuel test program, the Biofuel program logo remains on the tail to this day. Both of these liveries were made to work with denissoliveira's AV-8B Harrier variant pack mod. That is why the nose cone is missing by default, the mod is required for these liveries. Here is the link to this great mod:
https://www.digitalcombatsimulator.com/en/files/3339262/
The mod by default has the nose for the R+ slightly too long. Alongside the liveries comes an updated LUA file for the AV8B that goes into the main directory to fix this slight issue.