THAT so far was more informative than ANYTHING else. Thank-you..
So here is what recently happened...
I was able to finally add a mod to each of my sabers.. The off hand weapon, AFTER I added the mod, gave me a second augment.. So the first I put in, I forget what it is called, upped my mastery, and endurance.. Mastery is what I am going for.. Then, it gave me a chance to add an aug slot.. SO, does that mean there is another mod I can add? or would it remove the one there, and change it out? If I can add another, what would it be? I found the very first I added by accident.. and thanks everyone for all of your help so far..