Looks odd to see one buyer, only buy from one seller, for the last six years plus years. It is interesting to see how many other non winning auctions he bid on for this seller. If any one buyer bids on only one seller's auctions and ends up placing multiple bids on multiple auctions most of which he does not win then I'd suspect more attention is needed.
Where is the proof asked Ed? Take a look at auction 14369509 a winner. See a familiar bidder? Try 14315017, 14315008, 14291366, 14315018 he lost all of these. I picked ten recent completed auctions for the seller. You can go back as far as you like All the ones above have one common bidder. He did not win any other auctions but did bid on them. Either he loves this sellers stuff or he is stalking him. Since he has not won any other auctions, from any other sellers, in the last six years, I doubt he has bid on very many others. He might win one by accident and have a new seller feedback. But they both might be legit, sometimes a cigar is a cigar. When in doubt just refuse to bid on the sellers auctions. Don't caught up in their games.
I've seen several sellers who have multiple id's. Some buy under one name or ID and sell under the other. Some use the same name on multiple sites and some use a different name on every site. I pay a lot of attention to location. Rare for two sellers to both be in the same town. Also watch for repeated use of the same photos by more than one seller. We all note the same gun being sold several times by the same seller. Non payment is one reason, return under a 3 day inspection period is another. But if it happens too often you begin to suspect a pattern.
So Ed do you see a possible pattern? As to contacting Gun Auction or GunBroker don't bother. They give lip service at best. And I understand their position. A seller is a source of income, a buyer is not. Who do you think they have a vested interest in?