I have dealt alot with Olcoin on ebay. He's a good man and knows his nickels. He has three listed in his store: BU 1968 D 4+ FULL BOLD STEPS $95.00 OLCOINS PLACE 1968-D 5+ STEPS JEFFERSON NICKEL $495.00 OLCOINS PLACE BU 1968-D 5 FULL STEPS JEFFERSON NICKEL++RARE++ $1,895.00 OLCOINS PLACE I sure wish I could attend the show your planning on selling it at , I've seen some very excellent BU 1938-Present nickel sets go for in the neighborhood of $600-$700 dollars. When you start adding in full steps the price goes up exponentially Also: the Red Book doesn't go into step prices at all just BU, it has a little disclaimer about "full step nickels sell for a sizeable premium" Good Luck
If these are full step you'll probably get weak offers at a coin show. While there are hundreds or thousands of collectors for things like buffalo nickels and large cents there are few collectors for moderns. Sure you can sell raw moderns easily enough but you aren't going to find an interested buyer at the typical mid-size coin show. Even if you did, the offer will be supressed because the coins are raw. If they're no question gems with full steps and you have an interested buyer you'd do well to get 70% of their value, but neither of these conditions will apply in all probability. There are a mere handfull of modern dealers. I'd strongly recommend that you contact one of them. Good luck.
Carl I don't doubt for a minute that they laughed at you when you quote those prices. But ya know what - you find one of the harder dates and get it slabbed by NGC or PCGS as FS - and it'll sell in the thousands if sold on Heritage or at one of the larger auctions. Then you can be the one laughing - all the way to the bank