Boy did you ever give it your best! And it's really not possible to trap a cat when you have no idea where he really is! Someone, I mean the next volunteer or owner is going to have to spot him and lure him somewhere with food and get him on a regular feeding schedule. That's about all I can figure. Well, spot him, pop a cat food cat that instant so he hears it, stops in his tracks, sees the food go down on the ground, person backs off to let him come forward to eat A LITTLE (you said he is skittish of people), then if the area is too busy, somehow follow him at a safe distance and trap when he is in a quiet, non- interuptive (traffic, pedestrians) area...? If not too busy, go back to car to set trap with rest of food and when he's done eating the biteful on the ground, let him see the empty can in one's hand, pretending to put the can where the morsel of food was, then quietly set the trap down and return to car to watch. Won't work if is in middle of a sidewalk where people are walking by but off to the side along edge of driveway usually works cuz they feel safe and hidden. So tell Jackie good luck.
did you tell jackie you're out of time on this especially with no team effort? If so, what did she say? Does she not lay in bed at night and think about her house cat getting slammed by a car? Or grabbed by a coyote with no front claws to defend himself? Or with winter coming, no experience with frigid weather and snow and sub-zero winds? Ok. Rant over. You can print this and give it to her from me if you want. You done good!