Kilroy Industries has sadly, ceased production. (UPDATE: See below) They had a small but promising range of Old West buildings. Tending towards 25mm rather than 28mm, they worked better with some ranges of figures than others.
They were modular in design, so you could mix and match, but the buildings were all pretty similar, the differences being numbers of windows, and door placement.
They also came with floors (which many don't) but the floors were flat and had the company name engraved into them.
Doors were also moulded closed, although they could be opened easily enough.
The walls were very much thinner than most resin kits, and the window frames were very delicate.
The 'Zang's Beer' signs were copied from a period original. I assume it was as colourful as possible.
The boot was also copied from a period original, and is in fact photoshopped from a scan of a picture of the original sign.
UPDATE: Kilroy is willing to do short runs. Contact email@example.com to inquire about prices.