Yes, you can list it on GB, but there are several considerations to keep in mind. First, if you have never sold or bought anything on GB, you have no record which means many buyers will be reluctant to bid serious money. It's not uncommon to see items from folks with no record receive few bids and/or sell for less than they should because of this problem. Second, there are scammers galore on GB. There are lots of things that can go wrong and without an established record, some folks will try to take advantage of a "newbie." Third, you have to give GB your credit card number to sell with them. Lots of folks don't like to give out their cc info. these days. Fourth, if you sell it on GB, you're going to have to send it to the winner. That means more costs. Either you send it yourself to an FFL which means you pay FedEx or UPS rates, or you pay a local FFL to send it for you. Yes, you can pass on the cost to the buyer, but there are costs in both time and money. Fifth, if you set a healthy reserve and if someone meets that reserve and buys it, there is still the possibility that the bidder will be unhappy with it an return it. GB requires you offer a return privilege. Some folks simply ignore it, but it's there and represents the potential for a problem. Remember those scammers I mentioned, well some folks bid on stuff, win it and then either complain about it until the seller returns part of their money or they return it with parts missing and/or damaged. In some cases, the scammer just returns a piece of junk and then demands a refund, claiming that the item was not as represented. Sixth, I might have left out something, so go the web and look up consumer comments about GB. I'm sure that you'll be impressed. Now that you know about what a great place GB is, sure, go ahead and list it there. Personally, as the victim of more than my share of scammers on GB, I will never buy or sell anything there.
Another option is the on-line auction site Gunauction.com. It is smaller than GB and has all of the same problems for the person who is listing something themselves for the first time. But… there are a couple of dealers there such as a fellow known as "Jack the Dog" who take items and list them for folks. He does all the work, for a commission of course. The advantage is that he has such a good reputation that folks are willing to bid higher with him than they would if the same item were listed with another seller. There are a couple of other sellers there who provide the same service and produce very good results. I have purchased things from this site but never sold anything there or used any of the dealers offering their sales expertise. Check out this website, especially Jackthedogs listings and watch what happens. In fact, there is another seller who currently has a luger listed very similar to yours for $2700. I think this is the third or fourth time he has listed it without any bidders.
Yet another option is the large auction houses. I have sold and purchased items through several of the large auction houses that have speciality gun auctions. In all of my dealings with them, I've only had one problem and that was admittedly my fault. Which one you choose, in large part, depends on two things: 1). where you are geographically because one of these firms may be close to you; and 2) which one will charge the lowest commission while providing the widest exposure. The ones that I have used, in no particular order, are: Cowan's Auctions, Poulin Antique Auctions, Heritage Auction, Rock Island Auction, Little John's Auction, Carol Watson's Orange Coast Auctions, J.C. Devine Auctions, and Amoskeag Auctions. Several of these companies post their items on Proxibid.com. That offers the nation-wide exposure to buyers but leaves them to deal with the headaches. In fact, there are several lugers currently listed on Proxibid. Check out each of the companies and see if one is close to you. Best of luck!