Hi, this is a tough question, maybe answered better on the S&W forum. Many would tell you that gun in the condition you described it in is worth $200-250 tops. But...those guns were re-imported into the US in the 80's by I think Southern Ohio Gun, and were selling them for that price then, and with inflation on guns being what it is, and this being 2005, 20 years later one would think you could get $400.00 for it, easy.
Don't know one way or the other, but here is something to think about. I was at a Des Moines Iowa gun show last year (notorious for having just junk shotguns and worn out deer rifles), and a fellow had a Brazilian marked 1917 S&W in the same shape. I looked at it, liked it, but passed on it. He was asking $300.00. Later in the day I saw the same fellow sans pistol. I asked him what he got for it, $200.00 was his reply.
Later I saw the same gun he'd sold to one of the dealers, and he had it out on the table, with a price tag of $650.00
The blue book is just a guide, and one that is outdated at best!