It was published in 1997, note that it's "Edition Two." I've never seen the first edition, so I'm not sure if the Royo attribution is made there as well. I don't recall seeing it made in any other glass books, with the exception of a few price guides (that I probably wouldn't put a lot of credence into them anyhow). I do not believe Royo is mentioned in the Mergle Moser book (excellent book BTW).
The quality isn't the same as known Moser pieces I've seen or own, but I wonder if the glass could possibly be lower end Moser blanks (going out on a limb here)?