There aren't very many bolt mismatches worth over $1k. Maybe only BSW and K/G date rifles can command that pricing. DOU 43 is a common receiver code. I usually don't advocate for reneging, but you might want to walk away from this one...
Meh, that's poor form....if you bid, you bid....and if he wins at this price, yeah, its no bargain, but if OP wants it bad enough, its not horrible....he would be getting an apparently mismatched bayo and scabbard, and it does come fully equipped with a repro sling, and who knows if repro or not hood and rod...ao, and the stripper clips. So that helps a bit on the price.
Its a decent looking gun, not beat, so it has that going for it.
The way prices are going, it'll probably catch up in a few years....
I certainly wouldn't bid anymore on it, and its possible there is shill bidding going on with the other NR bidder. It would be interesting to see if the other NR bidder "wins" if the OP doesn't get a message in a week or so saying he can have it for his high bid with some reason why the "winner" backed out....
Again, its a case where I, and many others here wouldn't pay that much, but maybe the OP's circumstances are different...OP, let us know how it ends up!