
fortunately, this backstamp is not uncommon, so had you simply said that it was the 'Waterford' gothic mark, we would have known exactly, even without a picture.
Looks like your light source is too sharp and bright - this is why all the 'David Baileys' of this world use umbrellas to mute/diffuse the light..........not cos it's raining..... it keeps ample light but avoids the glare. Then, for a close-up, you need that all important lens.
It's not just a case of shining a light at your glass - that will obviously give the glare you don't want, so rather than incandescent stuff from a bulb, try a fluorescent tube - daylight are probably best, and then go in close.
There was some extended chat some 2 - 3 years back all about the best set up for photographing glass - we've had some real pros here, but not I think now. Try the Board's search - am sure you'll get good information.