Do you know what part is damaged, normally a speedo cable is independent of the speedo drive.
In your first two photos where it shows the drive it looks similar to the type used in Peugeot gearboxes where they had a rubber pin that was removed to allow the cable to be withdrawn from the drive end , it fitted in the hole visible outside the gearbox end of the drive.
So it may be an idea to see if drive or cable is the damaged part assuming yours does come apart from the drive end where I believe.
If so then searching similar models of Peugeot or Citroen van versions may increase your chances of locating a part.