Parachutes are pretty basic, and especially in those days when they were all round canopies, they were all fairly similar. So anyone who was familiar with any type should easily be able to figure out any of them. Back chute harnesses are all about the same, so if you know how to put one on then you do. A few of them had slightly different chest strap attachments, but nothing that should befuddle anyone. Anyone making an intentional jump, sport or paratrooper, would have a back main with D-rings for a front reserve. A military pilot or crewman, or a sport aerobatic flyer (such as Hayden) does not intend to jump, so the back bailout rig they would use is a reserve, so they don't have D-rings. A sport jumper at somewhere like Elsinore would not use a bailout rig, but they would see them being worn by either the pilots or people just taking observer rides (and landing with the airplane).
It sounds to me like he was asking for two rigs, mains and reserves. However, Flyjack presents other possibilities...