I'm going to print what you wrote and study it over coffee in the morning.
But - Since I worked so hard on my 'big post', I'm going to post it anyway. It might give you an idea of where I'm going. Lord knows I don't know!
Let me see if I get this right.
The meat packing plant does great being supplied with livestock from Arton and Middleton.
I need the paper mill because the flour mill and sugar refinery needs paper. I have to get either pulpwood or hemp to the paper mill to produce the paper, that is until 1920 when it requires the addition of chemicals.
The chemical plant needs alcohol and pulpwood, alcohol and gum, or 1 coal to produce chemicals (going with only coal seems to produce nothing). Alcohol needs either grain & lumber - until 1939, then grain & glass or grain & aluminum for the brewery, or produce-or sugar & lumber, then glass for the distillery Glass needs sand and coal, or chemicals, or aluminum.
Then I need the flour mill to produce by supplying it with grain & textiles-or paper or corn & textiles-or paper.
Then the food processor comes in, and it needs milk-or meat and flour until 1920 which it then needs the addition of plastic.
The plastic plant needs pulpwood-or hemp and chemicals until 1921 in which it then needs gum-or oil and chemicals.
The ports supply gum if supplied with food.
All of these need machinery, which by default is only at ports and in limited supply, so a need to build a machine shop comes into the agenda, which it requires steel and textiles-or rubber until 1930, then it requires aluminum & electronics starting in 1910.
Steel requires coal and iron. Aluminum requires bauxite, textiles require cotton or wool or hemp and rubber until 1930 then it requires plastic, and electronics require coal, petroleum, glass, and machinery.
Rubber requires gum, which requires food, which requires meat-or milk and flour (which requires grain or corn and textiles or paper) and plastics (which requires pulpwood or hemp and chemicals until 1921, then it's gum or oil and chemicals).
So, just to get food going I need to run rail from Arton and Middleton to Erin with the rail supplying livestock to Erin for the meat packing plant. Then build track to Silibury Bay and Eastport (to get as much machinery as possible until I can build a machine shop) and supply Silibury Bay with pulpwood or hemp from Middleton (or beyond if you can afford to lay the track) for the paper. Then the paper goes to the flour mill so I need to get grain and/or corn to it from Arton and/or Middleton.
Then I need to get the flour from Silibury Bay to the food processing plant, along with some meat from Erin, then - after 1920 I need to get plastic to it as well (I can swap food for gum at the ports). This necessitates the building of a chemical plant and a plastics factory.
Plastics needs chemicals as well as gum and/or oil (oil seems to be no problem).
Chemicals needs coal – or – pulpwood and/or gum and alcohol.
Here's where I run into a problem. I can't get the chemical plant to produce squat! I feed it with a dedicated coal train and get no chemicals. I tried feeding it with alcohol and pulpwood, but I can't get a distillery to produce because I'm too broke to get near the sugar refinery.
Thing is; Without the chemical plant the chain starts to break down. Paper, plastics, fertilizer, sugar, etc. all die out from not being fed.
Maybe I'm going about it wrong. Could be I'm still scratching my head over this industry structure, but if my trains would make a tad more money I could probably keep my head a little more above water.