This is what I've been working on:
This is freelanced, but patterned after Maine 2' drawings of flats. The real point of this is creating jigs that will allow me to "mass produce" several of these cars (and then write an article on the jigs.) Part of the challenge has been understanding HOn30/N scale "Geometry" to get coupler height correct.
Still to be added: stake pockets (sides are pre-drilled), NBW castings and brake wheel.
The 4-wheeler to the right is a British 009 kit that got me re-hooked on HOn30. It's styrene. The loco is a conversion on an N-scale Bachmann 0-4-0 Docksider that I got about 10 years ago on eBay.