I just got a nice used o5 super z, model 927012, serial 03112519. The 60" side discharge deck has a mulch kit installed. The blades are offset ( not straight). I am in near Cincinnati, OH, cutting at 3.5". What mods could I do to improve the cut or mulch? Mulch blade type/ spacer kit needed? Opening mod ? I would like to buy a Parts manual, but see the correct one isn't on the web. This is John Deere and Exmark country and I want this great machine to show its stuff! Thanks!