These are from an O-scale model railroad plastic kit. It's the Hobo Jungle from Bachmann's Plasticville USA series. Despite its horrifyingly bad name, there are a few good models in the Plasticville range.
According to the TMP All About Scales page, O-scale is supposed to be 1/43.5 scale or equivalent to 37mm miniatures. In practice, these are great with the 32mm Malifaux figures and fit well alongside Mordheim terrain (intended for 28mm). They're quite small overall, and most of our 32mm figures won't fit through the doorways.
I'm not sure how brown can be described as "bright," but I think some of these turned out brighter than I intended. The rusted metal turned out well enough, though the rust may be a bit too "fresh" looking... or just too bright.
I also have a Plasticville