Son sold deceased father's house in California during 2023.  Father was a Non-Resident Alien who did NOT have an ITIN or SSN.  At the time of the sale, there was no EIN and the escrow holder withheld 15% of the price at closing per IRS regulations.  Son is a US Resident and capital gain on the sale would result in taxes being less than the 15% amount that was withheld.  Do I use Form 1041 and is the son eligible for a refund of the difference?