Mooncrest , not an engineer ... But used Trident headsets for 12 years . Seem to remember there were a couple of types . One had a single metal piece over the top from left to right , the other had 2 overhead pieces , for and aft .
They all had Nato plugs . Have 2 of the 2 piece overhead types , converted to 2 plugs . They still work well for pax in the back of the school PA28s . Grey colour, squareish earpieces with a bright metal boom and about a 1'' square mic.
Have wx canx all todays lessons , so won't be able to find the make until I'm next up 't field .
rgds condor .