Just started a Garnock tug kit, The die cut styrene sheets are warped and misshapen, any ideas on how to flatten them out, first time ive used plastic sheet, i am more used to wood. If any one has built one, what size motor was used,as the supplied prop is a tiny plastic thing, I am thinking of changing it for a bronze one, if I can find one small enough!(it is mutch smaller than the kort nozzle, perhaps a slightly bigger Prop would be better).