As of June 28, 2021, I own the Series 1 Casascius 1 BTC coin with the address beginning with 17E9BEio. I bought it from an anonymous person in 2013.

JohnGalt on bitcointalk.org

19mzFU4zFrZHkAkHSUta6LapJ6fTFJyhiH
H5zjvt/A4CgQ3+5wNmridHzwv0ZZ5B9KTq+O0tPMUipIPXokyxGMO400p2En+aFXqWHXPFC6ZgtpbNKGX5Vfq2k=