These will not work for replacements for your aging PS1 controllers. The hole is too small to fit the original metal stick on the thumb stick boxes. The original small hole sticks use a flattened round stick (similar to a canoe paddle). These simply have a rectangular hole without the wider bit in the middle of the hole. The hole is also not wide enough for even the tip of the original stick to fit.
I bought these hoping someone was actually selling replacements, but these do not work. The search continues.