A friend of mine gave me a zippo lighter from a Marine unit, hoping I could find and return it to...

Here's another resource:
https://marines.togetherweserved.com/usmc/servlet/tws.webapp.WebApp?

Also this website:
https://www.3rdmaw.marines.mil/Units/MAG-16/VMM-165/History/

UPDATE:

Thanks to some helpful responses here, I was able at least to contact the current Squadron Duty Officer for that unit. Hopefully he will call me back with more information. I think has was taken aback that an old Army guy would take an interest in helping out a Marine or finding his family to return the lighter to after all these years. If he ever gets to a combat AOO, he will understand the cross-service bond. It lasts forever.