HI! Your research seems very sound. Harrachov made a whole range of this style of glass in crystal, with the distinctive stems, Glassobssessed posted some wine glasses that match exactly a few weeks ago and they were ID'd as Harrachov, Harrachov being the source of Harrtil too, your covered goblet looks simply to be a crystal version without the netting, a lovely thing. In crystal it seems the design originated a few years before Harrtil, circa 1950.
Robert (bOBA)