Alphonse Plomb left the company (black-smith shop), he co-founded in 1907, around 1917. Started his own company & branded the tools A. PLOMB. Sold to CALIF-TOOL around 1927. So, this wrench could be from between 1917 and 1927...
Porcelain Sign for Louisville and Nashville Railroad (started in 1850) -- Merged into CSX Transportation in the latter half of the last century (mostly operating in eastern half of the US)...