I can provide you with the images.
Do you mean the Civil War Battle of Murfreesboro sim by GMT or the “other” Dead of Winter ?
If the former, there already is a module for that one.
Dead of Winter A Crossroad Game
After seeing this game on Tabletop, I’d love to play(test) it. never worked with vassal scripting but might take a peek at it to help you. (I don’t own the game, however.)
Do you know how to code?
In various languages.