The Wargear mod works as it uses the ending clip of the first mission to manually add warfear to your existing collection. By editing that file, the mod tricks the game into giving you the extra wargear. The only way for the additional wargear to be added is to replay the campaign from the beginning, that way the game can do its thing and give you the wargear. That being said, any existing game saves or whatnot, will not have the wargear. Also, there is a limit to how many wargear items you can add. You will know if it is successful, as it will show you the stuff when you finish the first mission.
the wargear list though, is not that fully complete. I once remember that someone post more wargear list in the relic message board but after I change my computer I'm unable to find that list. If some one have seen it please can u post a list??
as I recall, the authour also replicate many of a wargear called "Wing of shrike" so that by selling it the marine will be at level 20 in no time