Tomarack, many thanks for your kind words. I cannot remember which book the cross section was in as I now have about five of those books each dealing with slightly different subjects and I am at work and away from my resources intil next March. The books are superb for getting to the detail of how such vessels were put together and giving excellent guidance as to how you can model them.
If you haven't yet looked try this link to a site that has a wealth of superb photographs of steam ships of the period I am interested in. Not only are there one or two of specific ships from the company that owned Doris Thomas but there are a lot of close up pictures that will be invaluable for creating the correctly realistic and weathered finish of the ship. They make you realise just how well used these vessels were.
http://www.rhiw.com/website_maps/ships_photos.htm
Look at the "Short Sea Vessels" section.
Apologies for not replying to your PM yet, I haven't forgotten it but busy at work so haven't had time. I will reply to it though.