What are the characteristics of Mr. and Mrs. Radley in "To Kill a Mockingbird"? (Physical and mental traits.)

Since none of the characters ever speak with the Radley's directly, it's only assumption that we can go on.  Since the Radley's are "Foot Washin' Baptists" that means that "anything pleasurable is a sin."  They do not go out much, they forbid their son to go out because of his mistakes in his youth, and the only person ever seen out is Mr. Radley.  He is only seen coming back with a bag of groceries once in a while.  After that, the only time they were seen leaving was when they were taken away in death.