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#1 is built by ARI (successor to AC&F), early-mid 2000s design. Not Trinity. No models exist in any scale.
#2 is an ACF centreflow plastics hoppers. Atlas just came out with some similar cars in HO. The Walthers plastic pellet car is a National Steel Car prototype. Different car.
#3 is a relatively modern (1990s-2000) hopper built by Trenton Works (Greenbrier). No one makes a model of this.
I'd say they sat somewhere for a really long time! The second one almost looks like commisioned art. It's interesting that the second car, which was done by someone with some real artistic talent, was also done carefully, so it didn't obscure the reporting marks or warning markings. The first one just covered the whole car, and his worked got tagged over by other gangbangers. The third one just looks like typical grafitti "art" but this guy also painted over everything, including the reporting marks. The BNSF hopper looks more like the work of the guy who did the season's greetings car. Notice that he was also careful not to cover any of the reporting marks, data, and even the reflective tape at the bottom. Although I'm not a big fan of any grafitti, it's nice to see that some taggers realize that some of the markings on the cars are important.
If they are grain cars, they sit most of the year on sidings by grain elevators before the fall harvest rush is on. I don't know how many covered hoppers I saw last summer while on vacation back in Illinois just sitting on sidings in every small town along the CN (old IC) mainlines. The taggers have unlimited time and access to these cars.