Rail cars are written in lower case on their page, so that's probably how they should be elsewhere.
Articles with "the" in the title are generally linked for the whole thing, including the word "the", so the Dressmaker should be too.
We tend to link to the whole name the first time a link is used. As Trimble's occupations was already mentioned, his first name should be too.
Because there is no "the" in the title, it shouldn't be linked there.
I have been trying to be very careful with my edits today so as not to "nitpick", I thought I'd leave this here just so you can see what my reasoning behind the edits was, and point out where I've gone wrong so I can avoid doing such things again.
1) Rail cars in that location begin the sentence... so unless grammar rules have changed somewhere, then that was wrong.
2) You flip back and forth the "the". This has happened several times on your edits, and is both confusing and inconsistent. For example you list the Dressmaker, which is fine... but the article of The Undine also has "THE" in the tile, yet you kicked that.
I'm not sure what your second last paragraph was trying to say, or how that influenced your edit, so I can't comment on that.
Rails begins the sentence, cars does not, but I didn't realise I got that wrong during the edit. My bad. Can we un-capitalise cars, at least?
We don't have an official ruling on that one I think is the main issue, so I have to go by what it seems is generally done. For the Undine, I know I don't like the idea of having half the hyperlink italicised, so I only do Undine and we only call the Dreadful Wale's page "Dreadful Wale", not "The Dreadful Wale". A bit roundabout, yes, but it does make sense to me. Could we just get an official ruling on linking or not linking "the" in articles? It would make things easier for everyone, I reckon.
For Trimble, we tend to use the full name for a link first time it appears (e.g. "Kirin Jindosh", then afterwards just "Jindosh"), yet we only use "Trimble" as the link to "William Trimble". I know it's made more confusing by the fact that he's often called "Nure Trimble", but as his occupation is mentioned immediately before his name, so the page should probably say "...as his nurse, William Trimble.", not "as his nurse, Trimble." like it currently does. Again, it's a thing that's generally done but not actually in the MoS.