In the opening scene when we see Jack and Victor as small boys and then turning into old men, look at Victor when he is a small boy. At one point he looks at the crew. It is over in a split second. Blink and you will miss it.
In series 5 in the episode "Hard Nuts," when Jack and Victor are deciding what they are going to watch on TV that night, look at the programme list. You can see that "Chewin' the Fat" is listed. Ford Kiernan and Greg Hemphill also starred in this.