Here's a unique one for you, a Thrall X79 boxcar, from Railyard Models.

These cars were built during the dark days of Penn Central's bankruptcy, when they were leasing cars rather than buying them.  To ensure adequate availability of rolling stock, Kellogg's ( the cereal company ) purchased a fleet of boxcars from Thrall and in turn, leased them to Penn Central for hauling their own product.  The cars were 60' double plug door models, designed for carrying large boxes of lightweight cargo.  As Conrail took over, the original Penn Central paint remained intact, often with patched reporting marks being quickly applied, until they reverted back to the KELX reporting marks.  However, there is evidence that a small number of these cars received full repaints by Conrail.  The only documentation of this was photographed by Gene Fusco, owner of Railyard models as a few cars sat in Hollidaysburg, PA, having been painted over AGAIN.  He was able to piece together what the scheme looked like, which is the scheme I modeled.

These cars were painted and worked on in the Meadville, PA shops in 1977, and since my modeling era is around 1980, the car didn't need a hefty amount of weathering.  Honestly, I needed to paint over a prior attempt at a Penn Central paint job on this, hence the slightly thick appearance of the details, and the obvious underlying PC markings.  This may have really been the way the cars looked though, since CR wasn't the actual car owner and may have been trying to dress them up rather than go through a full prime and paint.  I faded the actual paint color to save a step and help the decals retain their brightness as Conrails' lettering paint was often a much better in the  long term than the body color. There's some washes and chalks to suggest grime, and some nastiness on the roof since they usually didn't do much up top.

Earlier this week, Railyard models announced that they were ceasing operations and production of their infamous cast resin model kits, including this car.  Long prized by craftsman-style modelers, these kits blend the finest resin casting ever made with etched metal and styrene components, led by clear instructions and thoroughly researched prototype information.  If you want a chance at picking one up, keep your eye on his website, and ebay where anything leftover after orders are filled will be sold off.