From an ID on Davistown museum for a thickness gage,
""EINAR HANSON" "-TOOLS-" "WORCHESTER. MASS"
...
"Einar B. Hanson was superintendent of the factory established by
his brother, H. L. Hanson (b. 1881) who rented a room and some machinery at No. 54 Hermon street, Worchester, MA, where he
began the manufacture of piano hardware. He expanded and moved to No. 25 Union street. Mr. Hanson was the originator of many
taps and dies (Nutt, Charles. History of Worcester and its people, Vol. 3)."