I actually had the opportunity to look at this shotgun in person back in October. I consulted with Dr. Jim and came to all of the same conclusions that Mike outlined. As soon as I saw the "RE" serial number and extractors, I knew the gun was far from original. In addition to all that's been mentioned, the forend has a non-Specialty checkering pattern (non-L.C. Smith, for that matter) and and is of the 1940's fuller, more rounded shape. It also has almost no spring tension on it (from the J spring) and it never would have left the factory that way. I'm pretty convinced the forend was replaced with factory parts (including wood) - but not at the factory. It's harder to see in the picture Mike posted, but the 3" chamber stamp is pretty shallow, too, and all of the chamber stamps on guns I own or have seen are much more positive. I'll post one that I took that I think shows it better. All of the wood has also been refinished, albeit very well (may just have had a coat of oil added). The barrels and case colors look original and are excellent.
I even shared with the manager of the store all of the things that were wrong with it (he asked what I thought - wasn't trying to be a know-it-all) and he took notes and seemed really interested in the information. But, last I checked it was still for sale at the same price with no disclosures. The gun certainly has some value - especially with the box, carton, and paperwork (which all looked good to me), but probably not nearly what they're asking for it.