A. Neither MSCOMCTL.OCX nor MSCOMCT2.OCX are legally redistributable. They are installed as part of your legal MS Developer Studio 6 installation for you to be able to design and debug applications that rely on them for proper operation.
However they may not be bound into the bundle that your VB6 app installer fetches to the end user's computer for deployment together with your app and its dependencies. The end user is supposed to already have, or plan to have, a legal installation of those two controls on their computers. That's why you won't be able to find a legit 3rd-party source to download them from the net.
On account of that, legitimately free to use binary compatible custom replacements for the two libraries may still be in great demand among the law-abiding license-aware VB6 user base.