First, Welcome to the Forum
Next you do not have your location listed in your profile. So we have no idea if you are even in America.
Now since one of your requirements is wood grips and since most all current 686s ship with rubber grips, it leads me to ask if are you seeking used revolvers? Or new ones?
Are you willing to buy 686s with rubber grips and change them to wood yourself? Or must they have left the factory wearing wood?
Are you seeking production 686s or Performance Center models?
Consecutive PC revolvers is very easy since they are usually exclusive to a single distributor he has all the serial numbers. Lew Horton, Bangers, Camfour, RSR have always been very accommodating with my serial number requests. Talo is a different story.
If you are in or near where the NRA convention is going on right now, I would suggest you walk to the S&W booth and see if they could help you with this. Perhaps guide you to a friendly dealer in your area.
If you put out WTB ads on the various Forums, you might get a dealer to help you. Or at least you might get a dealer to keep his eyes open