Dolly Parton's vintage stage dress from 1980s

Hello Dolly-fans,
My late father was a huge Dolly Parton fan :) after he past away he left us with a stage costume, a fragile vintage dress with long bat sleeves. The story is that he bought the dress at an Elvis Presley auction early 1980s. He paid a lot of money for the dress at that time. Unfortunately there is nothing backing up the authenticity of the dress. What do you think? The signed photo is authentic - but picture not in good shape.
Appreciate any feed back or comments you might have.
Best regards
Christian