RGS: there is some real merit to recent posts about passing on the gun, but I gather from your first post that lust for this gun is high.
Here is another alternative to consider. Go back to seller and tell him you are concerned about re-sale value with a repair. Have him knock $2,500 off the price for a restocking job. There are alot of great stockmakers that will charge you about $2,000 labor for a complete stock job. You should be able to get a really nice piece of wood for $500 to $700. A good stock man can probably just replace the butt and match it to the forend. Labor for just the butt should run about $1,000 to $1,200.
Best of luck on this........ Chicago (Mike)
Let us know what you decided to do.