Door handles are one of those things that can interchange among a variety of models.
A-body & B-body handles largely interchange, with the difference being either in the angle where they meet the door or the connection for the rod on the backside of the push-button.
60-62 Valiant should be identical, but you might find that 62-65 B-bodies will also fit; maybe even later years.
I'd look at photos on Ebay, Classic Industries, Year One, etc.