hello, we seem to have two people using the tag line...."I'm new, please be gentle" - you're not Hugo's brother/sister by any chance, are you?

It can be helpful, sometimes, if we know the location from which the the request comes - to know the country is adequate.
That said, regret I don't have the answer you want, other than to say that the GMB does have its own marks and labels section, which is shown on the main page as 'Glass Reference Websites'. Your label shows a stylized thick upper case 'R' which has a similarity to the label for the Finnish factory Riihimaki - although your label shows what is in effect only half of the Finnish mark which is a back to back stylized 'R'.
So I doubt that your label is anything to do with Riihimaki - just that it had some similarity. From which country did you acquire this piece?