Kav - I bought an oilcooler grill from migsel for my 1150gsa: http://www.migsel.com/store/index.php?act=viewProd&productId=19
Instructions came with it. Managed to fit it without breaking anything - so must be easy. Have to remove bolts from the beak, move it forward and then the grill just slots in. I probably still have the instructions somewhere if you want them, let me know.
when you take it all to bits be careful not to double thread the screws trying to put it back together again You'll know all about it cos it rattle all the way to Vines to get more screws