I will have to look up the details. I know the MKT, MoPac and T&NO all had passenger service through Austin.
Sept 25, 1955 MP timetable The Texas Eagle from St. Louis (w/ Memphis connection) through Austin southbound at 10:33AM to San Antonio & Laredo (w connection to Mexico City) Northbound 3:43PM The Southerner from St. Louis (w/ Memphis connection) through Austin southbound at 3AM to San Antonio. Northbound 10:35PM
May 1, 1955 M-K-T timetable The Texas Special (joint train w Frisco) from Saint Louis & Dallas through Austin southbound 11:59AM to San Antonio Northbound 1:42PM The Bluebonnet from Kansas City & Dallas, through Austin southbound 2:18PM to San Antonio; Northbound 3PM The Katy Flyer from Saint Louis & Kansas City through Austin southbound 3:45AM northbound 12:32AM
My SP timetable from 1955 shows freight only between Houston and Austin anymore. I think SP passenger service was discontinued around 1950 or so except for football specials for the University of Texas. I will try to get exact dates.
OK, I found something. According to Steve Goen's "Texas & New Orleans Color Pictoraial" (SP) trains Nos. 42 & 43 between Houston and Austin were discontinued in November of 1949. Trains Nos. 45 & 46 between the same cities were discontinued on December 8, 1951. Neither of these were named trains.
Train # 43 departed Houston at 8:05 AM and arrived in Austin at 12:45 PM. It was turned and departed for Houston as # 42 at 2:05 PM arriving there at 6:45. Trains 45 & 46 were night trains offering Pullman service. I don't have times on those trains but do know the time was shifted to late afternoon after the # 42-43 were discontinued. All these trains were heavyweight.
Table 118 from the Feb. 1925 SP timetable lists trains 42-43 as the Hustler and 45-46 as the Owl. These are the same names as used on the Houston-Dallas trains. I guess SP dropped them sometime before WWII on the Austin trains to avoid confusion. This 1925 time table also shows passenger service going beyond Austin to Lampasas, Llano and Marble Falls.