Some plateau Clarinets were branded as "Normandy," but I think they are exactly the same as those labeled "Vito," as they were both made by LeBlanc in Wisconsin.
LeBlanc generally had 3 levels of “quality†in their clarinets.
Lowest were student model Vito, usually made of plastics
Second up was the Normandy, made of either resonite or wood
Top of the line was LeBlanc itself, generally referred to as LeBlanc Paris to distinguish it from the rest of the line. These were always made of wood.
There usually wasn’t much of a difference between resonite Vito and Normandy models. Maybe a bit better quality control or something, but not enough to really make a big difference.
There was sometimes a “cascade†of quality, as I call it. This refers to instruments that couldn’t pass quality control being rebranded as one level below.
So for example you may have something that started life as a LeBlanc Paris but something was up and it became a Normandy 4 or something. And then you’d have Normandy get knocked down to Vito VSP, for example.