CH stands for Champion
Contact the Kennel Club if you are having problems finding the lines Buddy has been bred from because if he has CH dogs mentioned on his pedigree then they will be registered with the KC. You can pay to have a longer generation sent to you or failing that, pick out one of the CH names on his pedigree and type it into Google, something is bound to show up which will help you trace his lines and maybe put you into contact with stud dog owners used so you can get more info
Sandy