Pencarrow
Western Thunderer
After seeing the photos on CRT's website I would go for Slaters as the tumblehome is more consistent along the length of the body and the profile is accurate where the flattened brake compartment side meets the carriage tumblehome.
Slaters kits 7C023 and 7C027 will make up P sets 179, 180, 199 and 200. More info here at SEMG online: http://www.semgonline.com/coach/maunco99.html
I've seen CRT's 'Thanet' set and was not overly impressed as the tumblehome flattened towards the centre of the coach.
Edit - to add hyperlink
I would agree. I did have a CRT coach kit on my shopping list one Telford and decided to leave it in the end.
I've gone for the Slater's Maunsell coaches. I think the transition between the tumblehome and the flat side of the guards section suits an injection moulding.