To me it looks like Billy Glide very likely did practice PE, in particular jelqing. I know I've read some small percentage of men are born with it, but men who jelq often develop what is known as 'turkey neck'. That is what is visible on the underside of Billy Glides penis connecting to his balls.
When you jelq, if you technique isn't 100% perfect and you accidently grasp a bit of the ball skin when you about to begin you next stroke, you also end up enlarging the balls up to the underside of the penis as you can see with Billy in the above photo.