Sorry to hear you think everyone that is muscular is on a shitload of gear. Don't make assumptions on other people's genetics. Plus, when you have built the base of muscle (assisted or not) its easier to get it back. Even doubling your testosterone will allow you to make gains. Normal young adults produce the equivalent of about 80-90mg of test per week so if someone was doing 200mg per week (very high range of HRT) they would have more than double their typical test levels. Being 60, he's probably producing half the test he did in his 20s so supplementing a small amount will make a big difference. Its futile arguing how much he is on, my arguement is that he can look like that on small amounts of gear with hard training and proper nutrition because of his base and his genetics.
Guys that are abusing gear do not look like Bill Grant. Additionally, we see his arms, not the rest of his body. His arms have always been big so its a genetic strongpoint.