I should qualify that this is very hypothetical at this point since I already have some many projects under way and am thus reluctant to commit to any more at the moment, but it’s fun to think things through before we do them, so what the heck.
We could probably fairly easily make a mold and cast a few of these from @zredthunder’s, cut them off and hollow them out and then mate them together with a hinge. The tox uthat looks to be cast clear resin that has then been machined with a standard drill bit. Or the master may possibly have been machined and those holes built into the mold. It would just require a very flexible silicone with a high tear strength.