Can anyone tell me if you can enter a finished AKC champion that has been spayed/neutered in the breed class?
Thanks.

Read your AKC Applying to Dog Shows to find the answer, specifically Section 8

A spayed or castrated dog may not compete at any show and will be disqualified except for entry in the Stud Dog and Brood Bitch classes. In addition, only at independent specialties, or at those all-breed shows which do not offer competitive classes beyond Best Of Breed, may spayed or neutered dogs be allowed to compete in Veterans Classes.