There could be more out there, but here are the few I know of that have hit the hobby:
Eddie Gilliand's ring sold in 2011 and 2013 in auctions. He was a front office executive.
Lubie Veal's ring was sold in 2011 by auction.
Jay Weaver's ring was sold privately in 2011. According to my notes, he was a staff employee.
I am not sure of any others out there or any that are available now.
A great resource to see if any other rings (or other sports memorabilia) you are looking for has sold and for what price is:
https://www.pricerealized.com/#/home
I believe the last three years are free, and their information goes back much longer if you sign up and pay for their services.
Good luck!