But it's going to be long ...
Yes, you may have a hard time both finding old bar neon lights and adding lightsources to make it look real. A lot of time and lots of try and fail. I know I would.But it all depends on your ambition level and need for quality renderings. If you are willing to live with lower quality, there is a possible compromise.
Make a box with a front texture and inside boxes with different colours. Add a couple of lightsources inside the coloured boxes.
Now the front texture is a canvas where you can use raster software (like the Gimp) to write or draw transparent patterns in a .png or .gif file.
Put the different textures on the boxes. That way the light will shine through and look like light signs, if not exactly proper neon signs.
If the texture is mapped to 100% of the front surface, you can also scale the sign to different ratios (but beware the scaling of the lightsource that tends to end up beyond the box borders).
Yes, yes, I know. Nowhere as elegant as other projects, such as the ghost city, but it is quick (and dirty) and takes up very little file space. The rendering, however, can still be pretty sluggish depening on how many lightsources you wish to play with. NOTE that the below examples are quick illustrations not intended to produce high quality results. With some editing the look could improve, if not to the standards some here would require.
In case some of the pros want to contribute proper models, I created a ticket in SF 3D models 453.
ok
Demo file: bar_neon.sh3d
Texture files (low res) - transparency written on a black canvas.
