So I'm refinishing my sisters hardwood floors and while the 2nd floor / stairs is solid red oak, the first floor is this engineered wood flooring. Not sure if it's pine or white oak or hickory maybe ? Really just want to make sure I can sand this without messing up her floor. Looks like there is an 1/8" of hardwood as shown in 1st pic. Also the previous home owner left a small section of red oak on the first floor for some shelf they built there. Should I just replace this small section with similar engineered wood flooring before staining? If someone has any input it would be much appreciated! Thanks.