This putter has an aluminum head and an iron hosel that is affixed with a pin low in the neck. The irregular shape given to the base of the hosel helps affix the hosel to the head. The aluminum head provided the golfer with a soft feel when striking the ball. The iron hosel provided durability. Aluminum hosels were soft and prone to cracking because they were thin around their top perimeter. 

This is the only example of this putter design known to the auctioneer, and is the very club pictured and discussed in TCA2 V2 page 430.  A signed copy of the page from the book is included with this club.