Droid 3 Backup Loss

Maybe a month or so ago, I rooted my D3 and put MavROM on it. Later my friend got Hashcode's CM9 ROM, and I thought it was pretty cool so I got it as well. After a while, I started noticing problems (e.g., keyboard randomly stops working) that made the ROM increasingly frustrating to use. A few days ago, I wiped CM9 off and put MavROM back. I also considered simply going back to stock, and so I turned off safe system to try it out. Well, it was boot looping.

I noticed that I had put my backup on my external SD card, and even though it hasn't happened before, I think Safestrap wiped it, along with my backup and orig system. How do I get a new stock ROM in place of my old one?