Warped 12 String Neck On A 1275

I recently acquired an Epiphone EG-1275 doubleneck. Unfortunately, the 12 string neck was cracked during shipping. Long story short, the crack has been repaired, and the neck seems very stable. However, there is an issue with fret buzz and there appears to be a bit of a back bow to the neck. My question is this: has anyone here encountered a similar problem, and if so, how easily was the problem fixed? Presently, the action in the 12 string neck has to be higher than normal to compensate for the fret buzz. I really want to restore this guitar to it's original condition. Otherwise, it's in excellent shape and it sounds wonderful. Here's a pic of my guitar:

Any input would be greatly appreciated.

TIA, Heather

I haven't experienced this problem myself. But if I were trying to fix it myself, here are a couple of ideas I would consider:

-can the truss rod be adjusted to take out the relief and straighten the neck back up ? (best option )

-if not, maybe you could put the neck in a jig, heat it up and bend it back straight

-maybe you could compensate with a fret level ? (quick but not ideal)

-remove the frets, sand the neck flat, refret