I was a little skeptical myself because this guide hasn't been updated in a while, but I decided to give it a try on an old rooted Charge of mine and sure enough, it worked great and it's now back on stock. As of today the links still work. As always, it will delete all of your info so backup before you start! Following the whole thing you'll have to take some OTA updates, but you'll be back on stock.
I just wanted to give a little assurance to anyone else out there who may be looking to get back to stock but isn't sure about the older guides. Follow the instructions and you'll be good to go!
Flashing Roms or Return to Stock with Odin BY PICTURE
EDIT> I didn't really pay attention to what I was running on the phone before. I believe it was Tweaked 3.0.