I hope no revenoors are reading this. Your transfer was illegal.
In California or any similar Fascist State that would be true, but in some States of the Union a "paperless" transaction would be totally legal.
It's easy to fall into the trap of thinking everyone in America is under the same laws, but we're not.
In fact, many people have tremendous difficulty understanding that people in other countries live fundamentally very different lives and think in very different ways. This provincial thinking isn't just "to-may-to" vs "to-mah-to", its like the difference between "live and let live" vs "Join my religion or I will kill you."
This seems to be the biggest challenge facing humans today, and a prudent man will be prepared by "keeping his powder dry."
The OP got a stunning gun in a fair trade -- because both participants walked away happy. I have a modest collection which includes a very fun variety of pistols and revolvers, and when I start selling them off (because I have no one to leave them to) my Smiths (a 29-2, a 19-2, a 15-2, and a 37) will be the last to go. None of them belonged to family, but they all have stories, and the J-frame belonged to a girlfriend, who has since passed away.
Yes, they are just things. I have a friend who said he couldn't understand why people collected antiques. He was born in Berlin in 1930, and when he was growing up no one wanted things that were "old." That stuff went into the trash.
I told him that for some people antiques connected them to a different time and or place. It's not the thing, it's the connection. My 1916 P08 Luger "feels" like history. My 1927 Martin Sax feels differently than a new one. When an item was owned and maybe cherished by a loved one, the connection is personal.
These feelings we have are why, when selling something cherished, we often want assurance that the buyer will cherish it as well. Buyers know this and will often say something like: "I love this and will keep it forever," even though they plan on flipping it, and already have a buyer in mind.
Such is the nature of humans...