won the auction and had a really good chat with the auctioneer. He completely agreed that it was a really big problem with mismatched serial numbers and offered to cancel the bid.
So I felt after the conversation that I had the following options:
1: Cancel the transaction immediately.
2: Buy the watch and then get an "Extract from the achieve".
If serial numbers didn't match their records, then I could also get a refund later on, since the item was incorrectly described.
If the serial number matched, then I would have gotten a "cheap watch" at the minimum auction price.
The risk, however, was that Omega could neither confirm nor deny the serial number. (Their records are not complete) Then I would be left with a watch that I could not return.
Therefore, I chose to cancel the transaction.
The auctioneer stated that he will go back to the sellers and have him get an "Extract from the achives". IF the seller can obtain this, the watch will be auctioned again.