Here is a nice, rather rare, harness jack bearing the stamp of Clauss Cutlery co. Fremont Ohio USA. Clauss is manufacturer and wholesaler started around 1880's and active till today. The interesting history of Clauss can be read here http://en.wikipedia.org/wiki/Clauss_Cutlery_Company According to the information I gathered, Clauss pocket knives were made by Case, Challenge, Robeson and perhaps by S & M also.
This knife is most probably made by Case on Tested XX era (1920-40), it is similar to Case model 62074 1/2 PU. The knife is 3.5" closed and the blade and punch are pretty full. The bone is what Case used to call green bone and the jigging is typical to Case. Also note the similarity of the shield to Case.

Mike