LGW (Leinauer Glaswaren in Bavaria)
It's
Leinauer
Glas
Waren. You can read about them in the article I wrote via that url I gave.
In essence, the maker of the glass is not the same firm as the iridiser of the glass. LGW bought in blanks from other companies and iridised the items. I bought a gorgeous vase a few weeks ago which is LGW iridised on what is possibly a Cristal d'Arques "blank". I'll try and get a photo sometime (I'm a bit rushed today).
Glen