Episode: 2.10: A Killer Named Cuddles
Trevor Cobb observes "In one episode a school party appears in a Bedford SB/Duple in full West Wight(of the Isle of Wight) livery of grey and red. I am not sure if it was still operated by them or had been recently sold out of service." Lloyd Penfold notes this coach "was acquired from West Wight in February 1984......It is now restored into the livery of its original 1958 owner, the Sandwell Motor Co of Handsworth, Birmingham."
The storyline concerns a school party visiting a safari park, which has its packed lunches looted by the park's baboons. As described, it's VVP911, in the livery of West Wight of the Isle of Wight, a 1958 Bedford SB3 with Duple body: