i dont have an answer to what glue would be best, but on my p700 i just put a seat cover on it and called it good. My seat got wet inside from washing which was ok during the summer months but really sucked when winter rolls around and temps drop below freezing. The seat cover not only holds the two pieces of the seat together it keeps the inner foam from getting wet. I dont know whats available for the p1k's but I went with the genuine honda cover for the p700.