The Strike Back Express and Royal Scot 

On 29th July 2017 Hastings Diesels ran the Strike Back Express to raise money for cancer from Hastings Via Reading to Bath and Keynasham then ECS to Bristol.
On the same day steam locomotive 46100 Royal Scot rand an ECS working from Southall to Bristol with a Class 33 (33207) leading. At Bristol the combination was split and Royal Scot ran to the West Somerset Railway.
I managed to catch both trains at Reading and Bristol and along with a few other trains I saw that day they are all on this film