I've had this piece for a while now, but so far I've not been able to find much about Leunox. One or two articles suggest it may be an alternative name for Leune used on lighting glass, but these don't cite sources & hence don't seem very reliable.
I was hoping somebody might have more information about this mark. I've seen a few other Leunox bowls, there's one on ebay now in a different design but with similar modelling and opalescence (item 290494816824). Unlike a lot of the other lesser known names that turn up on French Opalescent glass, e.g. Arrers, Vallon, etc., this doesn't seem to have been made at Choisy-le-Roi. The opalescence, finishing and general feel of the glass are all a little different from my marked Etling bowls.
Thanks,
Steven