Most Fitgirl repacks come with a basic offline mode, but add-on missions are better.
Since the 1.7.3 build is older, you should look for these classic SP projects that were compatible with that era: Most Fitgirl repacks come with a basic offline
Here is how you can set up and enjoy single-player content on this specific build. Why Play Single Player on Build 1.7.3? Most Fitgirl repacks come with a basic offline
(Build 1.7.3), specifically for the version often found in community repacks. Review: DayZ Single Player Missions (Build 1.7.3) Most Fitgirl repacks come with a basic offline