Tom Selleck was 24 in The Movie Murderer when he played the character 'Mike Beaudine'.
That was over 54 years ago in 1970.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 79, and has starred in 69 movies in total, 68 of those since The Movie Murderer was released.
In The Movie Murderer, I think Tom Selleck looks: