$600 tax/Venmo/PayPal

Forty years ago I bought an airgun for $500. I can sell it for almost $1000 now. 1980s 500 adjusted is worth more than 1000 now. Do I profit if I sell it? I actually have the receipt for it but who would normally? If I don't have a receipt and sell it IRS will tax me according to my income for the year.
And suffer a loss that can't be declared.


1 Samuel 8: 10-18 It's all right there in ink. He knew