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 (see And The Putter Went Ping  p 92-94, 100.

This Karsten Co Dalehead Anser was made under that agreement. The sole is marked both "Jack Nicklaus" and "Slazenger." The PING grip is a replacement. The 35" shaft is original and still has a good portion of its original shaft band.  The "Made in USA" has been ground off the back cavity as this particular club was shafted and gripped in the UK to help keep British import duties down.  

Jack Nicklaus PING putters are wonderful history and eminently collectible.