Lowell has now announced the Texas Special dining car. the first release includes Katy’s “Sam Houston”: https://lowellsmith.net/product/rsm-sam-houston-texas-special-diner/
Lowell has announced two more Texas Special coaches: https://lowellsmith.net/product/texas-special-coach-pair-2/ this time the cars are both Frisco cars, “Olivette” and “Pasadena Hills” Paul