Great detective work, thanks, but I did already have an idea 

I own a Godin LGX, and that's pretty much it, I mean: there's no serial number, barely a piece of transparent sticky tape on the back of the headstock that says "LGX'. I've tried www.guitardating.com, but it doesn't work without serial number does it ? I still want to know when the guitar was built though. Any suggestions ?