I would not be the least bit surprised if it turned out LANG made those for Stahlwille, or Stahlwille made them under license from LANG.
Do they have a patent number stamped on them anywhere? If so, just plug the patent number into Google and if it comes up "John Lang" you've got your answer.
I posted a long-winded diatribe about those a while back in the "Ebay Hot Deal" thread. (here:
https://www.garagejournal.com/forum/showthread.php?p=5720596#post5720596 )
Short story: other than the 'dog bone" (plastic-edged) older Craftsman models, almost every one of those was made by LANG (formerly Kastar) in Racine, Wisconsin.