Thanks Jordan, and to everyone else who reponded. That photo will help a lot.
I realize now that I should've mentioned the vehicle involved. Unfortunately, it's the prototype CMP 6x6 FAT that I'm building a model of and the only reference photo I have (thanks to Jordan) doesn't show the latching style, as per the attached. The vehicle was based on the C60x chassis though, if that makes a difference in body style from what Jordan has posted.
One further question. Did these drop tailgates drop all the way open or were there chains or something similar to hold them open on the horizontal, much like pickup truck tailgates?
https://i.imgur.com/NxYUsrt.jpg