The Inventors Mansion at SDC/DW first opened in 1979 at the bottom of Craftsmen's Valley. It was the 3rd attraction added to Silver Dollar City Tennessee since the name change. The rides started with the first being the Flooded Mine in 1977, Blazing Fury 1978, and then "The Great Inventors Mansion" 1979.
According to a map I have from the 1986, the first season of Dollywood, it shows the Inventors Mansion attraction gone and replaced with Dolly Parton's "Rages to Riches" Dolly Parton Story Museum within the same building the Inventors Mansion previously occupied.
In 2002, Dollywood Blvd. was renovated into Adventures in Imagination and featured the "Chasing Rainbows" Dolly Parton Museum. This is the time that the museum moved from the Mansion into the new area.
I am really not 100% sure of anything else that was in the building after 2002 till the present. I have heard it was used for meeting space and storage, but don't quote me on that!
To this day, the mansion still sits high on the hill overlooking Rivertown Junction and surrounding areas and you can still walk through the cave underneath it that connects Craftsmen's Valley and The Village.
I hope that this helps!