Why did you cross a Thai and Tex only to try to get back to Thai Silk? Shape, vigor?
If you want to get back to Thai silk, you can backcross the offspring back to the Thai silk parent. For instance, if the Thai silk was a male, you backcross his daughter.
If that doesn’t work, you may have to do the opposite and get a male offspring and outcross to a female Thai Silk.
At least that’s my understanding.
Hybridfish7
or
HybridFinatic
would likely know better