He most likely isn't using anything crazy. Probably a low dosage of testosterone, some primo and HGH. The reason he looks as good as he does for his age is consistency. He probably never let himself ever really get out of shape and has been training consistently and eating properly for 30+ years.
My dad looks like my older brother. People don't believe his age when he tells them it. There is no secret to it. He has just been following a healthy diet and training regularly his entire life.