Well, having returned yesterday from MIA, I find myself this morning, sat on the floor with a coffee and about 25 books littered around me ... big deception because not a word is mentioned about this type of glass.... not even in the book from Joseph Philippe, which is considered by many as the VSL Bible.... I'll never open it again!

... I definitely would have expected to find something in this book

There are a few examples in catalogues from the 30ies, where it is only mentioned that the item is made of 'Cristal Urane' but nothing further on colour schemes, design patterns or even basically the production ... it's from my contact at VSL, a 'maitre-tailleur' that I have heard, that they stopped using uranium oxide for health reasons, and if I'm not mistaken, this was in the 30ies/40ies.
It is true that designs from this period often have a central decorative point, as mentioned above, but for me personally, this is not enough to say it is or it isn't VSL .... my gut instinct says it isn't but one has never seen everything and I've been wrong before.... so as they say over here ... je me réserve ...
I need to return to VSL, to have a couple of items repolished and I'll ask again this week ... also, the shop's still open (funny that, the factory's closed for production right now, but they continue selling) and behind the counter, there's an office where they keep a lot of catalogues. One of the ladies working there has been kind enough in the past to help me out with any questions I had, but the other one is practically wearing a 'Do not disturb' sign, so if I'm lucky, and if you don't mind me showing the images in this thread, I'll ask for further information, and see what they can tell me.... fingers crossed.