I only have a few artglass catalogues (paperweights being my main topic) and a few price lists (not necessarily same years).
Haven't found the vase and/or bowl in any of my catalogues - so, without image, I cannot be sure ... but
I have found code 7820 in the 1999 price list: "Horizon" Teardrop Vase: the shape (teardrop) fits - so if anyone in possession of the 1999 catalogue could check, we may have tracked it down.
The range also includes
7821 Bud Vase, and
7822 Round Bowl - which would fit images shown in this thread.
Height of the Teardrop Vase should be 192 mm, and the diameter of the Round Bowl 144 mm: would these fit your items?
The range is not mentioned in the 1998 price list - don't have art glass info 2000 - but the range is not in the 2001 catalogue - so it seems to have been in production for a short while only.