With a thin vertical alignment flange or fin that extends 3 inches straight back from the middle of the face, this early 1900s putter appears to be one of a kind. 

The first thing to know about this club is that the flange has been welded onto the back of the blade.  It was placed directly over the middle of a now unreadable name stamped on the back of the head. This tells us the the club was originally made as a blade putter.

The second thing to know is that the flange was installed shortly after this club was made.  The patina on the flange is old, original, and exactly the same as that on the rest of the head—and the finish/patina on the head has not been messed with.  

The third thing to know is the addition of this flange was professionally executed.  The flange is beautiful in form, neatly affixed, and well engineered.  When you look at the flange as it is attached to the back of the blade, the flange looks to have a uniform slope top and bottom as it extend back.  But it was crafted and attached so that when the golfer addresses the ball, the bottom of the flange angles up well away from the ground as it approaches its end while the top of the flange runs parallel to the ground all the way to its end.  Both of these features show a creative mind at work!  The level top of the flange provides the best alignment while the angled bottom of the flange prevents the flange from catching on the ground during the golfer's follow through.

The original shaft measures 34" long. The grip appears to have been covered with some type of old tape.  It is solidly affixed and actually "works" on this club. 

Home-made alterations to old golf clubs do not typically add much value.  This is because it is tough to date such alterations and there are those in recent years that have altered in an effort to deceive and gain more money on a less-than-forthcoming sale. The addition of the thin vertical alignment flange on this club, however, is neither amateurish nor accomplished in recent times. Not at all.  It's a genuine feature engineered and built into a club over 100 years ago and was used by a golfer passionate enough about his putting to be among the first to ever use such a strange looking weapon!  That's valuable history—and a vital part of the game.  

This club is in the middle of the top row of the group image.