Seiko 66-8040 replacement crystal

I have purchased three fantastic Seikos in need of new plexi glass.
I could find through another members post that one should have part number 310t48ang through this post:

But I have two more watches that I cannot find any reference on.
The watches serial number is 66-8040 and its diameter is 31mm.

I asked chatgpt and it says:

For your Seiko 66-8040 watch, the original…

Click to expand…

Seiko 66-8040 replacement crystal