Wait Three-Quarters Point ??
Are you sure? I think you are seriously underestimating a key aspect here. Even with all of the resources already made (models, the majority of VOs, sounds, and animations), the missions themselves will still take some time since you will no doubt have quite a bit of scripting to do and I doubt your campaign is just going to be a quick 5 missions, either.
I don't mean to rain on your parade; I'm giving you some perspective as to the amount of work left.