Karsten Solheim followed the 69 putter series with the B69, B68, B67, and B66 putters which he advertised as "Ballnamic Putters." [And The Putter Went...PING (2017) by Jeffery B. Ellis]. Offered in 1964, the B69-B66 putters were more heel-to-toe weighted than their 69 series cousins. Karsten filed for the patent on the B69-B66 designs in January 1965, and he received the patent on January 1966. 

This Scottsdale PING B69 putter is in very good condition. PING moved from Scottsdale to Phoenix in mid-1966, so this putter pre-dates that move. Therefore, Karsten only had a few months to produce this putter with the earliest Scottsdale address, which explains its rarity. 35.5".