Between October of 1966 and January of 1967, Jack Nicklaus won four professional championships using a Ping Cushion.  In early 1967, Karsten Solheim entered into an agreement with Mark McCormick, the agent for Jack Nicklaus and Gary Player, that allowed Slazenger of England to sell Ping putters bearing the endorsement of Nicklaus.  This agreement lasted approximately three years.   ATPWP  p 92-94, 100

The Cushin was introduced in mid-1965.  This Nicklaus Cushin shows some use, but is in good condition and presents well.  The PING grip is a replacement.