Money inherited from sale of property

My Dad passed away in 2021 and I am the only beneficiary of his estate.  At the time he passed away he had invested and was part owner of a house in another state that was to be a ‘flip’.  The house did not sell for another year and a half after he passed.  The proceeds from the sale of the flip house were sent to me as the executor of his estate and a 1099 was issued in my Dads name for $80,000 in profit made on the sale.  
I filed a tax return for the year he passed but did not know how to handle the 1099 so never filed a return for 2022, the 1099 was issued to him Dec 31, 2022.

Should I include the 1099 on my return (which I would rather not do amended returns) or complete a 2022 return for my Dad, but won’t tax be due on the 1099 ‘income’ then?

Since I inherited the property and it was sold a year and a half after he passed, isn’t my cost basis the value of his share at his date of death?

Thank you so much for any help with this.