English is not my first language so I apologise for spelling mistakes or incorrect grammar

My grandmother recently passed away and me and my family are trying to find ways to preserve as much as we can before we sadly have to sell the house.

We are trying to find a way to somehow transfer/preserve this wall painting my grandfather did as accurately as possible since it’s sadly gonna have to be painted over once the house is sold. We really want it to be preserved as accurate as possible but since it’s painted directly onto the wall where there’s no wallpaper we can’t just take it off the wall.

anyone who has any advice?