R S Gwynn wrote:
"Since CK refers to one Dr. Sutton as "Old Dr. Sutton," wouldn't that imply that there's also a young Dr. Sutton who is living in the same house as his presumably retired father?"
I don't believe so. In comment to line 119, the commentator writes "Two distinguished medical men, long retired from practice, dwelt on our hill", indicating two men both old and retired. Also, he writes that the name Sutton is "a recombination of letters taken from two names". If both men have the same name and/or live in the same house, why not say so?