This ad from mass-market clothier Galey & Lord dates from 1965. But apparently that’s no random model who sat for the portrait. According to textilehistory.org:
In the mid-1960s, six prominent socialites had their portraits painted by Henry Koehler. The garments were crafted using G&L fabrics. Ads appeared in the New York Times Feb 2, 1965.
If that’s your father, leave a comment and let us know.
(Postscript: Galey & Lord ad from six years later, after the fall.) — CC