I never met Hal Ambro, but I sure know his work, and I ilke it a lot.
He started to work for Disney in 1946. Even though he never reached the status of supervising animator there, his animation can often be found in sequences that were lead by such animators like Ollie Johnston (the opening section of Johnny Appleseed) and Milt Kahl (Ambro animated almost half of the footage of The Fairy Godmother in Cinderella).
I am quoting John Canemaker from his book "The Animated Raggedy Ann & Andy" from 1977:
Hal Ambro, in his early sixties, stops by the studio to pick up and deliver some Babette scenes. Ambro, a gentle Santa Claus look-alike, started at Disney and remained there until 1966. He decided to free-lance because "there is only so much room at the top of the ladder at Disney", and he wasn't going to reach those rarefied heights occupied by a select corps of Disney animators.
"I've had a lot of training in the human area in Disney films. Humans are most difficult in the sense that you have to elaborate- exaggerate is a better word- in their actions. But not too much. You don't make a face look like Jell-O, but you can do an action that reflects a stretch in the whole posture."
Ambro animated the character of Babette in that film, which was directed by Richard Williams.
During the years past Disney he also worked for Hanna Barbera and Chuck Jones.
He passed away in 1990.
Hal Ambro could draw. Look at this gorgeous drawing from one of his scenes in Lady and the Tramp. You can tell, this was drawn by somebody who loved what he was doing.