Baseball authentication. All or None?
 

Was wanting to know, what the general rule of thumb is on third party authenticators, and how they view a ball with multiple signatures?

Is it possible to send in a ball with multiple sigs, and ask them to only authenticate one signature? Or do they have to authenticate all sigs? I have an older ball, that I am confident that a few of the original key autos are legit...but that at some point in time, someone helped themselves and added a few of their own. (About 15 years later) It has definitely hurt the value of the ball....but was still hoping to get the one or two real autos certified/authenticated. Any help is appreciated.