You really need to hit both GunBroker.com and or AuctionArms.com, or I think there is at least one other one. But hit those first two, join them it's free, you just have to remember yet 2 more passwords (coming up with new passwords and adding them to my Vaults is what keeps me from joining most things.
Do a search, probably come up dry, BUT there is at least on GunBroker.com an auto search that you can set up to notify you when ever what ever it is you are looking for comes up for auction. OH YA! I just remembered the other one! GunsAmerica.com, actually they may not be an auction site but they have had some great prices for a couple CZ's I bought. And they also have an auto search that will look everday and then let you know when it finds the item.