It looks like the forend is curling around the bbl a bit. You can probably just pull it back into position and tape it as already mentioned and everything will be fine.
Personally,,I'd soak the forend in hot water first,,a tube or pipe with a closed end works good for this.
The warm wet wood will be easy to place back in it's rightful position with little force if any being so thin.
Plus will be more liable stay put in that position when dry.
It's the same idea gunsmiths use to bend the butt stocks on rifles and shotguns for their clients to change the drop, cast and cant, but they deal in measurements up to an inch or more sometimes and some very thick wood through the wrist area. They usually use hot linseed oil soak and heat lamps to get the same effect to the wood. Then clamps and braces to move the wood and let it cool.
Same result is wanted though,,move the wood permanently and not damage it.
You can coat the raw steel bbl with a thin coat of lacquer or even shellac to avoid rusting during the process. You many still get a touch of it but nothing that'll pit the surface.
Careful handling and securing the wood when it's wet as it'll bruise & dent easily. It'll retain it's original strength and form when dry.
Just a thought,,,
