Unless I'm mistaken, this version of the Cronin-Reach ball was not used until the end of Cronin's tenure from 1970-1973.
Cronin was only in office for 2-1/2 years before Cobb's passing which makes any Cobb signature on a Cronin very suspect.
http://www.ebay.com/itm/TY-COBB-Auth...item27d29a4d6f