I'll have to admit here I never saw the Kotelnik fight.

The reason I'll say I saw him age was because of his reflexes.

Sure in any Witter fight of any year there are times where he would do nothing, but he would be defensively minded in those periods and his footwork and reflexes would keep him out of trouble allowing him to win rounds on inactivity!
Last Sat. the relexes and speed were faded and if you watch the knockdown in slow, his legs were very weighty.