Here is the floor interior, as supplied by Bachmann, sitting on the chassis. Look how thick and how bright the floor is. Those prominent holes for lighting will be filled. It seems the seats in the Non-Smoking saloon were a patterned dark red and white (so a darkish pink or light maroon for me). The floor should apparently be red oxide which would have rapidly faded and/or muddied; presumably to a brownish light pink. Or am I wrong?
The original plan was to populate the coach with the expensive but excellent set of dedicated figures sold by ModelU. I thought the openness of the auto trailer merited good quality model people. These were duly acquired and a happy couple of days were spent painting them to a reasonable standard. Now I discover that the thick floor requires their feet to be cut off! I am not happy to do that considering the outlay of resources. So some less detailed figures will be used, their feet will be amputated and then represented with paint on the floor. The exceptions will be the poor (to be footless) driver who will be very visible in the cab and the fireman destined for the 64xx. The rest of the ModelU passengers are destined for the open saloon in the Maunsell pull-push set; hopefully they will keep their feet!