Permit me a few remarks, in no particular order, on gun show ethics.
Ask the exhibitor's permission to pick up an item, especially an expensive one. This puts you on good terms with the seller, right off, if you choose to buy.
Hold a gun by the grips or stock, touching the metal as little as possible. Always support a leather scabbard of a sword, bayonet or dagger when drawing the blade.
Don't dry fire a gun and NEVER load or attempt to load a gun! NEVER! If guns are tied, do not cut the tie; most show rules will allow the seller to cut the tie for a serious buyer, but the potential purchaser should not do so. Naturally, the rules about pointing guns applies always.
Do not spill a soft drink or mustard from a hot dog all over a $5000 gun. This does not make for friendly relations with the seller. Eat and drink in the areas set aside for that, not around the exhibits.
Dicker, but once you make an offer and it is accepted, that is it. No reneging on a deal.
Most sellers are honest. Some are a little shady, a few are downright crooks. Learn enough to know what you want and what you are looking at.
Some sellers may not be as knowledgable as you are. If you get something at a good price, buy it and say goodbye. Don't stand around telling everyone what a sucker the guy is. If you do, it won't happen again.
If you think the item is a fake, or not right in some way, just pass it up. Don't broadcast to the world that the guy is a crook, cheat, liar, and eats spaghetti with a spoon. If another potential customer asks your opinion of an item, you can say that you wouldn't buy it, but it is not your job to keep the rest of the world either educated or honest.
When you hear a real "story", just smile and say politely that you didn't know that Robert E. Lee used an M1 Carbine at Gettysburg, and walk away.
Jim