There's a website with details of making a new shutter blind it's not difficult at all. In my case I removed the blind, cleaned off a lot of flaking material, maybe someone had tried to repair it previously and seal pinholes etc, I used methylated spirits. I then ironed the cloth and re-sealed/light proofed it using a flexible acrylic black paint which soaked into the material. The woodwork was french polished before re-assembly and final adjustment.
This link is useful for general LF Focal plane shutter repair, but her's the TP shutter repair pages, I re-built mine before reading this
I'd add that the best cord I could find was for window blinds.
Hope that helps