You may be right, he may have had (presuming he never "left the building") work done – and hopefully, he never used either Pricilla’s plastic surgeon or Nancy Pelosi’s or Joan River’s or Michael Jacksons for that matter! Eeeeek!
I think perhaps though Elvis may have looked just that "rough" in his older days because of all the drugs and alcohol he did. That kind of life plays havoc on your body, (not to mention your mind). Maybe, he would have become more reclusive that he was the last couple of years before the end of the ’70s and we would have not had a picture or glimse of him in years.