Is it just the wrapper that is damaged or is the metal creased or dented?
If it is just the wrapper, re-wrap it.
I do not believe the battery that came with it is protected. It just has a slightly raised positive and so it looks like a button top. Any high drain flat top that can handle 10 amps should work fine in this flashlight .
I have Keeppower protected but I prefer to use my Shockli for a light such as you have which has LVP cutoff at 2.8 volt.