Sad to say my only Texas experience is Cooper's. Not that it wasn't great, but that that is the only one I have sampled. No Kreutz, no Smitty's, no anything else.
My brother lives just outside of Austin and took me to Cooper's.
Where are the other old school you speak of?
Cooper's, run by the Wooten's I think is not considered by anyone to be a MECCA. Maybe some marketers. They claim the old "BIG CHOP" restaurant as their heritage.
TEXAS MECCAS
Lockhart 2003 Texas Leg made this city, which holds the three oldest BBQ families in Texas) as capitol of BBQ in Texas.
Kreuz Market THE OLD BUILDING (Pronounced Krites) 1900 1999 Rick and Don Schmidt were forced to move to new Building.
Smittys - where the old Kruez Market was but when the Schmidt Family took it over it became Smittys Market in the late 40's.
In short the Kreuz Family started it then Schmidts bought it from them, renamed the old facilty Smittys market in 1948 then in 1999 had a fight with the Kreuz side and moved to a new building calling the new building Kreuz Market (reclaiming a portion of the coals from Smittys market, which was the old Kreuz market before 1948. They kept the name but the Scmidts oddly took the name of the Kreuz as a business.
Blacks (1932) Took the "longest family run BBQ" title away in 1999 when Smittys and Kreuz split.
Southside Market - Elgin, Texas (Vince Mares of the Taylor Cafe came from here in the 40's. Home of the famous Elgin sausage. started in 1886 or so but didn't get run continously until the 1940s.
Taylor Cafe - Taylor Texas also known locally as Vencil's.
Louie Mueller's BBQ 0 Taylor Texas
Sonny Bryan's BBQ - 1910, Dallas, an Oak Cliff location opened in 1935 and 1958 another
Angelos of Fort Worth 1957 (used to be my fav until I went to Lockhart) primarily this joint, which was a bar that had the coldest beer in Texas, served BBQ to sell more beer.