Looking for Richard L. Zimmerman

I am not quite sure exactly what I am looking for, but basically I am trying to help my grandfather find an old friend from the Army. I wish I could find all my grandpa's papers, but he was in Korea and helped rebuild in Inchon...he also was in (I want to call it) the 50th engineer brigade or something like that. He joined in the early 1950s and was also honorably discharged around that time. Also, my grandfather seems to remember that Richard Zimmerman was from Traverse City and the former owner of ZImmerman Construction Company and possibly moved to Columbus, OH? If any of this information sounds familiar please email me at [email protected]. My grandpa was telling me about this again at Christmas and he just had a heartattack the other day and is pretty sad...and finding an old friend just might be something to cheer him up:)

Thanks for your help!
Amy