I couldn't find any model number for the Second Victory Gundam therefore I added the "-2" up to LM312V04 to make it more realistic.
The Second Victory Gundam (aka Second V) is a mobile suit featured in the novelization of Mobile Suit Victory Gundam. It is piloted by Uso Ewin. - gundam.wikia.com
Second Victory Gundam Illustrated by Yanase Takayuki - see the original image below