Mark had it reproduced the correct way. It is a printed process not any type of etching, and the etching will not look anything like the original bird glass... but for anyone wanting a custom look etching would be a good option and the etching info is great advice.
As long as it's close enough where most won't know the difference, but not too close where some may try to pass it off as original and try to command original prices for it, I'm all for it...