I found something called Tear-aid for repairing Nylon (my suit is Cordura). This seat though is a mystery. My builder put a XL Tillet in but it is too large, but it presses against my rib vest in places. The hips are way too big and the seat seemed comfortable at first, but now it feels uncomfortable. I could buy seat pads and see if that fixes it, or I could buy the smaller L seat and try that.