I also sail a P-19 with the stock pinhead sails and the first thing I did was to replace the 7/16 mainsheet when I got it. I am running 5/16 dacron spun braid on a classic harken 7:1 switchable mainsheet system(original equipment). I normally only go out when its blowing over 15mph and always keep the rachet on and the cleat positioned so I can release the sheet easily. You may have to put a spacer under the cleat to get it right. My 7/16 sheet is now connected to my universal gymn and is part of my workout. Someday I'll upgrade to an 8:1 carbo system.