If you search around the internet, you'll find different fishing auction companies. The two that I'll mention here are the bigger ones that seem to offer quite a bit of variety. Rods, reels, books, & paraphernalia of all kinds including old flies, catalogs, creels, nets, etc can be found. Most of these auctioneers release there catalogs a month or so before the auction, so you can plan ahead.
Crossroads Angling Auction offers a lot to the angler & they show 'teaser' pictures of some of the stuff they have ahead of time. Their auction will be going off April 25-27, 2014.
Lang's Auction is probably the biggest in the nation (& the most attended / watched) of all the angling specific auctions. Lang's also offers a store where you can buy some items in the normal way (no bidding) periodically at different times throughout the year. Lang's spring auction is scheduled for May 17 & 18, 2014.
Both companies offer a "discovery" auction of different items that could include just about anything (except the really collectible items) that usually go off before the main event. They also offer you a few ways to bid which include over the phone, in person at the auction, or online in real time & you can also submit a bid ahead of time by mail.
You never know what will be up for bid at these & other auctions. If you're a collector, or are after something specific, then it's worth checking them out. Auctions can be fun & exciting but these fishing specific auctions are almost always educational, too.