In looking for 116 BCD chainrings for a friend of mine, I happened onto a Czech company that appears to make them to order. They are here, about halfway down the page: https://www.gebhardt.cz/cs/silnice-c...odniky-a-kryty

They are marketed in England through: https://www.soniccycles.co.uk/gebhardt.php
and were reviewed here: https://roadcyclinguk.com/gear/bkool...irst-look.html
He bought one of these through Hilary Stone so I didn't continue this research and I haven't tried to buy directly from Gebhardt or Sonic. Worth checking out though.