Engelhard advertising (or maybe for employees) letter opener.  I *think* it is stainless steel.  Has Engelhard logo on handle.  No other names or marks found.  Handle is sort of a matte finish (not shiny like the blade end).  Very good used condition- a few light surface scratches typical of use and storage, see photo. 
From what I gather, Engelhard is a Fortune 500 company located in New Jersey.  They are associated with precious metals (like silver, gold, etc...) and some chemical processes.  Parts, if not all, of the company were taken over by BASF in 2006.  Engelhard started in the early 1900s.  I'm not very familiar with this company- but if you are- you might need this ;) 
If you need additional photos or have any questions, please let me know.  I'll be happy to try to help.
From my non smoking home.