In December of 2020, I decided to seek out an address for Ken Berry. I sent him my card and the following letter.
Ken signed a 1990 Best Birmingham Barons Team Set card #28.
https://www.baseball-reference.com/players/b/berryke01.shtml
https://www.baseball-reference.com/players/b/berryke01.shtml
https://www.baseball-reference.com/register/player.fcgi?id=cafaro001rob
https://www.baseball-reference.com/register/player.fcgi?id=green-003tho
https://www.baseball-reference.com/register/player.fcgi?id=brown-001bry
https://www.baseball-reference.com/register/player.fcgi?id=white-007tho
I ended up writing and mailing out 11 letters that day. All addresses that I looked up myself, not listed on an autograph database, as far as I could tell.
I found what looked to be a legitimate address for Mr. Waggoner, so I wrote him a letter and included my card.https://www.baseball-reference.com/register/player.fcgi?id=waggon001aub