The drive-in was part of the Adelman theater circuit, which operated movie houses in Houston, Fort Worth, and Tulsa, as well as the Delman Theater (not a drive-in) in Dallas. Cost of construction was $150,000, which included innovations such as indirectly lighted walkways, a patio with lounge chairs, and a playground for children. I don't think they would have got away with that Snow White mural on their theater today!
Both the South Loop Drive-In and the Delman Theater closed about 1968, and no obvious trace remains of this theater in the field that still sits along Loop 12.
A couple of corrections from reader Matt Schaffer (schaffermatt54 @ gmail.com): The Delman persisted on into the 1980′s. Was a fine venue (and well-maintained/managed) til the end. After it closed as a movie theatre, it was operated for a while as a club. If I may offer a small correction re: exact location of the South Loop, historicaerials.com has photos that document it precisely – on the south side of E. Ledbetter. Here is the link to the photo – compare the route of Ledbetter in that photo with it presently on google maps (hasn’t changed) when you enter 3142 E. Ledbetter for the address.
Thanks to Matt I was able to find two aerial photos of the drive-in's location, one from 1952 when it was still new, and one from 1972 after it had been razed.