I recently thrifted this Venini decanter. I have been able to find similarly shaped bottles online, but none that have a smooth finish like this one. Is this bottle authentic or is it a forged? It about 11 inches tall and 4 inches wide. While it does have an acid stamp that dates it to the 50's or 60's, I know they can be faked; I am not well rehearsed in spotting the differences. Any input would be appreciated!!