Sub it out Mike, Dont turn it down. Sub it out and maybe spend a few days on site helping, get a feel for it. obviously you know how to do the work, but if you dont want the hassle, atleast try and get it done with someone else, then if anymore work comes from it they will come back to you, not go elsewhere.
As for the chewing gum, not much help pricing that sorry. I would probably price it in on time spent. How quickly could you get all the other work done?