I remember as a kid the Skeggy specials. Class 20s having a day off from the coalfields hauling a rake of Mk1s from Leicester, derby or Nottingham on a Saturday morning with a return journey in the afternoon. The heyday of that was probably EMT using HSTs to do that same thing. There was no first class fare for those routes so you 1st was declassified. Lovely experience. The 170 seem a come down in comparison, but times move on.