reclaimed

We are missing some flat coping stones from the parapet wall, as seen in this picture: https://imgur.com/a/kIEcmf9. I've tried a few reclamation yards around us (East London), and none of them have them, nor seem like they would ever get them How would you replace these?

Hey Guys. So I did have a question up on another part of the forum and uploaded content and pictures there. But i have decided to start a new thread, to make it easier to see and see my mistakes. Here goes. The Mrs wanted to change the flat, and have a space for her plants where the cat does...