MrEMD,
Well, I see no one has responded to your request for track, well let me step up to the plate try and explain something here as best I can.
Now I'm not trying to bust your bubble or anything like that, but, we have only a few 3d modelers around these here parts, and they will take on freeware projects they find interesting, fun, challenging or just sparkes there intrest in general. I know you want everything in route to be a one off, but to be blunt, unless you take up 3d modeling and do it yourself, or hire a team of builders, that just ain'ta gonna happen.

And no I'm not trying to be an smart a** here, I'm just being realistic.
Why because building assets is very time consuming endeavor, you can spends days building the mesh for one little item. Once the mess is compleated you then have to make the blueprint for the sim. Once the blueprint is finished or atleast working you can then get the item into the sim tweak the item from there. Change the shape here a little, change a color there and so on.
Now, you say you’re working a freeware route, so why not use the freeware that’s already out there? Take for instance track, 3dTrains has some great track and the best part is they have a free set, that, most everyone already has (or soon will.) So use that track for your route and tick that one off your list, it's done already.
The way I have seen most route builders take is they have one install for their main route, and another one for their assets (less payware items of course.) Is it a PITA for the route builder, well somewhat, but at least if you do things this way you will make sure of two things, one you have made it as easy as possible for the user's to install your route (not spending weeks trying to find an obscure model or route,) and two, you will make sure that all the assets you put into the route are there (no broken scenarios or milk bottles laying around.)
Best of luck to you on your route,
Roger