ME1 Reload Save and Beat the Game again, does it make another completed save?

So, my question is simple. Explanation may be a bit long. TL:DR at the bottom.

I have recently beaten the game and have done every single possible thing that I could except for UNC: Negotiation (cause apparently Hackett doesn't want to give it to me despite my Paragon points being maxed out). Probably a few other smaller things, but basically I did a lot in my playthrough (40hrs total) and I really, really, REALLY don't want to have to go through all those small assignments and everything again. Collecting, searching, etc.

Now, I beat the game with no romance, sacrificed Ashley and saved Kaiden.

However, before I even beat the game (at about 26hrs into the game) I saved it right before talking to Liara and locking in a romance with her.

I want to be able to reload that save (to bypass a lot of the stuff I already did) and romance Liara, save Ashley, and do all the extra content I up until I beat the game again.

So, since I beat the game already, it created a save I could import to ME2, correct? So if I reload that save as I mentioned above, and beat the game again after making the changes to my choices, does that completed save get overwritten or does it create a whole new save and when I go to import into ME2 I'll have 2 different saves?

I know that if you start a NG+ and beat the game again, it makes a new save, and if you create a whole new ID, but I'm not doing that so that's where my question lies.

TL;DR: If I have beaten the game already and made a completed save file, then reload an earlier save to make different choices and beat the game again, does it make two different completed save files or does it overwrite the save that was already completed?

I appreciate the help and answers.

To further elaborate, this would all be without going into NG+. If that wasn't clear. Thanks.