It is probably a very nice pistol that had been reworked by Wilson Combat, but WC never worked directly with S&W.
As such, it's not a "collectable", and in fact may be worth even less than a box stock 66 because most people prefer to buy the best condition, but totally stock, pistol of the model they want.
Once a pistol is reworked into something custom, then the potential size of your buyer base gets much smaller and you could find that it wouldn't bring even as much as a stock pistol.
On the other hand, if you personally really like the work done on that 66, then remember that someone actually paid real money to WC to do that work, so it "may" be worth more to you personally than a stock 66, and if so, then go ahead and pony up the cash and get it.
I think what you should consider is this: IF you were personally considering getting a 66 and then sending it off to WC for customizing and willing to pay what it took for that work to be done, then buy the one you found and you'll get by "cheap" even if you pay a premium for it. You'd still get by for less than if you bought a stock 66 and then paid the extra for WC to work on it.
Anyway, here's a little quote and link from the WC site that suggests that the pistol you are looking at was simply a revolver that someone bought new and then sent to WC for a rework:
Today is a good day to get started on your dream gun. Call one of our Customer Satisfaction Representatives and discuss YOUR dream gun and get an estimate of our current delivery schedule.
We work on customer supplied Colt*, Springfield Armory*, Kimber* or Smith & Wesson* pistols. We require a $50.00 deposit when you send in your pistol and Custom Work Order.
Build Your Dream Gun
Regards 18DAI
