A couple of comments about other photos:
The photo of 666 in post 70 is definitely at Newport as I have several other photos of 666, usually with it's sister 667, at the same location which have Newport written on the back.
Regarding photo of 386 in post 86. The second loco is ex Rhymney A, A1 or R rebuilt with standard GWR boiler, not ex Barry. The cab is higher than the Barry B1 and B behind. The odd Barry B1 was given a GWR boiler, but also received a full GWR cab.
The Rhymney loco in post 104 is a P1. One of the larger 5'3 passenger locos vs 4'6 freight locos. Compared to the freight locos it looks taller, but of course isn't. What gets me excited though is the ex Rhymney bogie coach behind it.