The 1858-S and 1853-O likely had PVC as both show corrosion. I don't see PVC on the Texas. What do you see on the Texas that makes you think that?
The discoloration is a similar Grey to PVC, there are some small green spots also. I don't think they are corroded, I think they could use some time in pure acetone.
A nice upgrade from my AG3. I couldn't resist this coin and am delighted to win it. Now I have to sell the other two to afford this one. PCGS VF25