Do a google search on firearm forums. Plenty of advice there, you should be able to identify what you have and find out if it's a rare find. Online sales happen everyday, but there are hoops you have to jump through.
Here in Va there is a web site dedicated to firearm sales in-state, as here if you do a face to face sale between folks that live in Va, no paper work involved. And yes, the feds know about that!
Each state has it's own law on the subject. Go to your states web site, that info should be there.
Folks who live somewhere other than NJ or Cali don't worry about big brother.
When you find out what it is, let us know.

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83 SD

84 CD