Thanks, all!
Mason, I'd be happy to share my sources with you. There aren't many period photos of old west Chinatowns so what I did was just sort of 'Orientalize' standard Old West buildings by adding details such as signs using a pulp-inspired font and the new block will have lanterns and other details added and I'd be happy to let you know how I did them.
I'm going to be 'demolishing' and re-doing the Chinatown block so I will have better detailed photos of it up when I do. The saloon on the block is way too big and I don't really like the layout in general. I'll be keeping the other buildings (and Mr Wu's pigpen out back!) and adding two or three smaller structures in place of the saloon.
Do a Google image search for Chinatowns. Most of the hits will be modern ones from New York and San Francisco but you can find lots of interesting details such as window and door frames, signs, decorations, paint schemes, etc.