Address the point in the first minutes of the interview and turn it into an advantage.
If the other part is nervous about your age, talk casually about how this will not be a problem. Be humble, calm, and redirige the conversation toward focusing in your best skills, from more modern to more old techniques. Skills that you can offer because you are not so young as the other candidates, and you love your job enough to keep trying even if you not became an unstable rockstar/diva programmer.
Agree that dying the hair a little, at his home would help. Just to pass from all white to some shade of grey. A 64 man with silky black hair would look ridiculous.
Someone else mentioned dressing less formally. He can work out. He could also dye his hair and... keep in mind the guy is fairly desperate here... wear makeup.
What would that entail?