^^^ That is a very nice assessmnet, 2152hq. The only thing I would add is what appears to be dissimilar coloring from the re-blue. This is unfortunately a common occurrence but, for me at least, it has a significant effect on desirability.
What's it worth? As the saying goes, it's worth what someone is willing to pay for it. In the case of an auction, it's worth what two people are willing to run it up to unless you start with a hefty reserve.
As far as value, it's a desirable model, caliber and barrel length. The engraving and inlays are certainly eye catching. As 2152hq has alluded to, however, there are several factors which will affect value. The engraving and inlays are good but not master level. The color variations in the bluing and the fact that the engraver is unknown affect value as well.
I'll take a stab at it. Others may think I'm being too conservative, but I would value the pistol in the $4,500 to $7,000 range depending on how it was marketed and sold. The $7,000 price being in a nationally advertised auction including buyers fees and the lower end being a private sale or a local auction.
I was once told by a gun dealer that it's much easier to buy a gun than it is to sell it. In this case, you need someone willing to open up his wallet and hand you thousands of dollars for your pistol. I have found that those willing to spend that kind of money get rather particular about the details mentioned above.
If this was my grandfather's pistol, I wouldn't worry about the value because it would not be for sale.