I think you will be fine with doing it for ten to twelve hours on the low setting . Once cold it should carve like a dream .A liitle stock is wise as it's quite a long cooking time and you can always add a little more from time to time .Just keep a weather eye on it !
Criss cross the fat ,brush it with honey and stud it with cloves .
Have a lovely Christmas Viv and Ron and all the best for the New Year .Happy slow cooking in 2007!
Shaney xx