That sounds very easy to believe, the government back then was very hardcore on making sure nothing made it back from the front lines.
Randy, I don't understand why they took that coin from you unless it had something that would be offensive to some on it like a swastika. I was in Libya around then and went to Germany after! Brought home coins from both countries without any problem!
I thought about it over the years and I rather am of the mind that the customs officer may have just been a coin collector himself!