My favorite:
And a Lykens Valley kit that I built:
This B&O pig flat was classed as an O-58 gondola by the B&O as it has sides:
This was built and hand-lettered (by Tommy Arnold?) in July 1939. Around the same time, he also built a couple of O-60 65' mill gons but I do not have a photo of mine. The only change/upgrade that I did to them was to install Athearn insulated trucks for two-rail operation.