There is a 1785 Census of the Colotlan region that is held at the 
Archives of Simanca in Spain and has bee digitized.

I was thinking that perhaps we could get a few volunteers from the 
group to help transcribe it and then perhaps even publish it.  I think 
it would be very useful for many people in the group and as far as I 
know, it has not previously been published.

The document can be found on Archivos Espanoles en Red at:

ES.47161.AGS/19.8//SGU,7015,2

Let me know if you are interested in helping out on this project.