What to do with a blown X03?

I blew my X03 by carelessly inserting the batteries backward. It still works, but it's completely unregulated. So I can use it with a single cell and a dummy with decreasing light as the battery discharges. But I'd like to make better use of it. I got it apart using the ingenious freezing method. The only active devices on the circuit board are a transistor and IC. I wasn't lucky -- the transistor is ok, so the IC must be blown. I doubt I'd be able to replace it even if I found a good one, due to the very small lead pitch.

Is there an off-the-shelf regulator I could put the emitter on and use to replace the existing one? Other ideas? I don't have a huge amount of time to spend at it, and I'm not able or equipped to do any but minor mechanical modifications. (Think Dremel.) But it's not very useful as-is, so if I completely ruin it in a mod attempt, it's no great loss.

Could you add a flupic to it,and run a 18650.Flupic is limited to 5v or less IIRC.I bet the sandwich shoppe could help.