Hi Rose,
I know - Chalet, Lorraine, EDAG , Mosaic - sooooooooooooo close. A really good hint re some of the Lorraine pieces (like your one here) is very often the "cut" lines on the sides are very wide and have "wavy, pebbled like" markings on the glass where it was finished. Chalet pieces never ever have this. You can see what I mean here on the Lorraine 2-tone spike and curl compared to the Chalet bowl. This colour combo was used very, very oftenby both companies but see how the colour placement is reversed - always true for both so that is also a way of helping id both these pieces. The thumbprints on the Lorraine centerpiece are also a good indicator BUT you will find those on the smaller Chalet ashtrays like on the Chalet signed 3 butt "clover" one here.
I think they did it knowing we would all need a challenge 50 years later!
Deborah