I have drawn up some basic carriage sides and roofs and some parts for a DE3 loco. I will get some pictures up.
My current idea is for a 12ft by 2ft layout with one side of the entire length being a platform - two lines run parallel to this and some points off to a carriage shed, loco shed and a siding or two - The idea is to have a loco come out the loco shed, refuel and sand, go to the caboose siding and haul it off to the far right end of the platform, then build up a consist of carriages (probably 5-8 depending on whether a local or international train is being built up) taken from the carriage shed (which will have a cassette storing 4 or 6 carriages) - Once built up, the idea is to take it apart again, send the loco back to the shed, swap it out with another and build a different train. The shed could also be used to store wagons to build up a goods train for variation. I will scan the two designs I have done so far for comments.
Wayne
West Wales
Plans, bottom one looks too busy - I like the angles on the upper one
Scan_20191105 (5) by Wayne, on Flickr
IMG_20180327_210437 by Wayne, on Flickr
IMG_20191101_114950 by Wayne, on Flickr
IMG_20191101_114433 by Wayne, on Flickr
IMG_20191101_114429 by Wayne, on Flickr