I have an old baseball signed by Casey Stengel & Fred Haney in the 1960's. How find out if authentic? Value?

I found this baseball when going through my late fathers things, i do not know the history on it. All i know is it as an official stamp, says "Official Special League Rubber Center" and it says no. 962. Through research, i found that this model ball was made sometime in the 1960's. I looked at copies of each of the players signatures online, Casey Stengel's is in blue ink and Fred Haney's is a blackish Grey ink. I am not interested in selling, my husband and i would like to p on to our kids but i would like to obtain some type of certificate of authenticity and get a general idea of the value.. i have pictures if you need more info. Thanks!