M-4 1931-mid 1930s (unclear, but they could have gone thru 1938). The Black handle driver, 5-1/8 length. The early ones have Snap on, stamped on the shaft. The later ones, have so on the shaft and blue point on the handle ring. In the mid 1930s there are some natural wood handles, the catalogs show them with a ball stop and what looks like a natural finish in the 1936 catalog thru the 1938 catalog. The 2nd photo is an M-4 1932 natural wood example and the 3rd Photo is an M-4 1936 with a natural finish and ball stop. This one is 5-3/8 in length and does not fit into the 9/32 case. Ran 1933 – 1936?
From the catalog the M-4 started in 1931 to the mid 1930s through a period that is unclear, but they could have gone thru 1938.
The Black handle driver, 5-1/8 length. The early ones have Snap on stamped on the shaft. The later ones have labeling – blue point – on the handle ring.
In the mid 1930s there are some natural wood handles, the catalogs show them with a ball stop and what looks like a natural finish in the 1936 catalog thru the 1938 catalog.
From the actual tools the actual situation looks more like this