Pendant Light Fixtures - - Replacing the Cord

I recently discovered one of my original gumdrop style pendant lights in the kitchen was dangerously frayed at the base, so I decided to take it down and replace the cord before it fell on its own.

Can any of you tell me if the original braided cloth lamp cord is still available or if you've found a suitable replacement of the same diameter?

I've tried plain black, round, extension cord, unfortunately it is just barely too thick to fit through the ceiling plate.

thanks,
Ramon