I'd have to dig up my Indiana Jones hat in order to locate my PRS/SSA/DPH covered hoppers, so here's a link to an image on the S Scale Sig website of an old Pacific Rail Shops ad, showing the hopper, along with two 50' boxcars.
http://sscale.org/images/TSSJ/v1-no2/PRSad1.jpg
Rusty