My father passed and left me this 410. I have his registration Form #1 stamped by the IRS and the ATF dated in April 1961. I have to say, this gun is an absolute blast to shoot!. I have no need and want to sell this gun. My questions are, 1) what do I need to do to "legally" sell this gun, 2) what is this gun worth when in excellent condition, and 3) what is the best way to find a buyer? Thanks for your help and information.