MBSO ex 7775, which I believe only came to SW in later years, whereas 7717 was a Bournemouth unit (in my time) before moving up to Womble land. Remember them very well in original large van/cage guise, although one section of seats in the revised format could make for a nice snug area of sorts (no external door in one bay). Interesting to see that the compo nearest the bog in the DTCL's has been retained as second class, judging by the external yellow lining. Can't remember now when those were first down classed, so very long ago!
PS: with apologies to StephenHunter - didn't see the attachment a few posts up!