I'm in Houston, right now, for a job but also to research Brendan's time here in the 70s. Since we got the packing done quickly, I've been able to haunt several book stores seeking info...and finding little. Brazos books had next to nothing. Kaboom had nothing at all. I wound up getting the most useful books at the Barnes & Noble in River Oaks, while I was driving around the area to get a better feel for it. His aunt and uncle live next to River Oaks, off Shepard.
I visited NASA, as well, and finally had some BBQ at a Rudy's that's not far from there. I didn't make it to the library. I've had 2 nosebleeds while in Houston and am now paranoid I'll get blood on a book. So I set myself up at a hotel near the airport, turned in my car and am staying near a sink, just to be safe. The second one wasn't nearly as bad as the first, but it's still unnerving. I now have an appointment with an ENT for the 29th. Get my nose cauterized, again.
I never did find any information about the master plan for Houston that came out in the middle 70s, showing major buildings to be built on the east end of downtown. That stopped with the financial collapse in '87 and didn't pick up speed until recently. But I did notice a number of new high-rise structures on that side of downtown, now.
I'll keep looking for it...but I have a map from the period and have a fair idea I'm doing all right on the details, so far.