I recall the first time I saw a film on a 747-100 (SAA JNB-LHR) and was amazed! The pneumatic headphones were GHASTLY and very uncomfortable. Later, I bought an attachment that plugged, had a battery and circuit board, mini-microphones and then you plugged your Walkman headphones into it. I also remember when VS introduced the personal Video8 player with a choice of films in Upper - must have been about 1989.
Yes, I did just catch the end of the silver service on one or two flights in the 1980s. But to get the real deal, you need to ask your question in the 'Cabin Crew' forum. They may have links to people that are now retired who could help.