John Schultz founded Schultz N.S.G. about 1898 in New York City. The location was 122 Nassau St., just a couple of doors down from A.G.Spalding & Co. John Schultz died in 1924 and the business was carried on by his son into the 1940's. In addition to stationary and gift items, Schultz carried a line of sporting goods. They became well known for their fishing gear and opened up a second store in Freeport, Long island in the 1930's. Below is a photo of the original building at 122 Nassau St
The Schultz baseball gloves are understandably scarce given their location as a small regional supplier. There is some mention of catalog sales, so Schultz gloves probably had some out of state distribution. Some really nice examples are on JD's Site, http://www.baseballglovecollector.com. This great looking D&M "Babe Ruth" model G41 sold for a princely sum on ebay a number of years ago. It has both the D&M and Schultz cloth patch on the back.
The KenWel model below shows a change in the Schultz logo in the 1930's.