Made by Karsten Solheim in the garage of his Redwood City home, this 1A no model is so called because the putter is a 1A but was not stamped 1A. This example, however is marked with an "F", for flat lie, on the toe of the sole. The club shows little use, and is a wonderful example of an iconic club.  It is one of the first putters hand-made by Karsten Solheim, with the help of his son John. 

The 1A putter was the beginning of the end for the once famed Bull's Eye, the number one putter in golf in the late 50s. when this 1A was produced. When the heel/toe-weighted 1A was introduced, golf entered into a gigantic sea-change. In 20 years time, Ping putters had become the most popular in the game. Clubmakers everywhere were making numerous heel/toe-weighted putters trying to keep up with Karsten, often copying his designs as close as they legally could. 

At the same time, true blade putters—those with their weight spread out evenly across the entire length of the blade—were in a death spiral.  This despite the fact that such blade putters, which were introduced in the late 1700s, had been the most popular putter design between 1890 and Karsten Solheim.

ATPWP p 28-36