There isn't much to know about copyright. If you don't have a license then you can't distribute a copyright work. Just because you can't find someone to give you a license is no excuse.
How does Cloanto know Franko doesn't have a license to distribute them? Did they ask? Or just complain?
Does CLoanto "own" the Copyright so do they even "have" the right to complain?
Flip side:
How do we know Cloanto have a license?
We don't own the copyright, so do we have a right to complain to Cloanto's ISP because we suspect they do not have a license to distribute and demand proof they do?
Second of all regarding Franko and a license for distributing copyright, I think you are missing the point. I think basically Franko is distributing these Workbench disks under "Public Domain".
Who's burden is it prove these are public domain? Franko's that they are, or Cloanto's that that just have a license to distribute, or the "Unknown" copyright holder that they are still copyrighted?
I think the problem is here, it's possible Cloanto has a license to distribute Kickstart images and disks, but at the same time the license is either made by ill-intentioned crooks from AI that know they don't hold the copyright or just ignorant of the fact that the disks went into the public domain 15+ years ago.
Either way, worst case scenario, if the Workbench is still copyrighted, I fail to see how a third party that just a has a license to sell a product can act on a copyright holders behalf.