Hello everyone. Looking at the Hornby mk3 coaches on Hattons web site I noticed one of the gwr green ones was labeled a tgs trailer guard second. Is this a coach that would have been in the formation or rake, whichever is the correct term, of a full length hst set between London and Cardiff in September of last year? or would it be tf x 2, a trub, then tso x 4 with a power car at each end like I was thinking? If I am correct would the tgs be a mk3a and only seen in a loco hauled train? Thanks in advance for any answers.