Curious where you got these? Also, I've never seen anything where she signed S. Nicks. (without using her first name).
I bought these from other collectors over the years. I have seen her sign S. Nicks as well as Stevie N. or even just Stevie. I'd place the date of the auto on the left as late 80's after rehab, and the one on the right is early 2000s. I recently upgraded to a really nice RAL signed in gold on the black dress so I'm considering parting with these.
Wow, she really is young there.