I think it would be a good idea to publicize an 'open call' for submissions from home & business owners in the area. They could be given a survey to fill out about their property to be reviewed for consideration. And then from there be submitted by the city and historic society to the Texas Historical Society to be set up as a genuine historical site.

I also feel that homes with the historical zone label, should not be able to split into multiple rental units. (ie, split into apartments with multiple entrances, kitchens, etc) but should remain as single family homes to maintain the property's original structure and style.
There are quite a few run-down houses that used to be glorious mansions on Oak & Hickory st but since they are now rentals, are only ghosts of their past. It's truly sad.