[Big D]

I posted this note on the Double Gun Site. So far, 135 looks, no response. Must be the most stupid, or most difficult question ever posted. The gun in question is a modern, sporting clays gun.
Hopefully, someone here will be able to help.

"My son-in-law banged up the stock of his clays gun over the weekend. Top of the comb, probably some broken fibers. We will attempt to steam out most of the damage, but my question is about the finish. I assume the gun is Poly-finished. Will steaming work without blowing up the finish? What can I use to refinish after the wood repair? Tru-oil, or do I have to go with a poly of some sort?
Thanks in advance for your ideas."