1877 Jim Devlin letter to Harry Wright
 

I came across the website haulsofshame.com . On the site is a section for the top 10 most wanted missing national baseball treasures.

http://haulsofshame.com/most_wanted.html

On the list is a 1877 Jim Devlin letter to Harry Wright, signed by Jim Devlin.
(the picture on the website is not a very good picture of the letter)
Devlin discusses fixing games and taking money for losing the games on purpose. He talks about his financial struggles and asks for forgiveness, among other things. The letter is signed by Devlin.

I am curious as to what a letter like this might sell for? Also, what kind of interest is there in old signed letters such as this one?