As a collector/researcher of ONLY glass hen on nest covered dishes, I really don't know much about other glass items....only what I pick up in passing and what will help me in attributing glass hen dishes. The researching of glass is complicated by our having so few primary source materials and by the imaginative speculation of many that is passed on like the game one played in school where the teacher whispered something to a child and that child whispered it to her/his neighbor and it was passed down the line until the last child said aloud what he was told. The last child's telling was seldom even close to what the teacher originally said! But, each child was positive that they heard and repeated the teacher's message exactly.
Alas...I get much too philosophical here! You want to know what the PV label means. I haven't a clue other than what I have found in print and from other researchers. I do know that PV has not been seen mould-marked into an item. I do know that the PV label appears on ceramic (porcelain?) items also. I know that the PV label has been seen on items that are also marked "made in England," "Made in Italy," and "Made in Czechosovakia."
A seller on eBay said that Godden's Encyclopedia of British Pottery and Porcelain Marks shows the mark as standing for "Pleasant Village." The PV mark has also been seen with "Porcelaine Limoges France" surrounding it. In the September 1979 issue of Glass Review, p.8, Steve Jennings shows a picture of a 1950s ad from Mitteldorfer Straus of 38 imported from France items. Steve says, "To the best of my knowledge, this is the same company that featured items with a sticker marked 'P.V. France,' which I take to mean the 'The Peasant Village.'"
I personally believe that it was used by an importer/exporter much the same as Shannon Crystal is used today for items made in the Czech Republic. I am sure that you are aware of other such uses of labels.
While we are puzzling over the PV label, let us consider the SV mark also. I have been told that more information about that mark, which may be a label or mould-marked into the item, is coming out next year in the form of a book. I do not know who is doing the writing/research or what the information will be. Let's hope it is definitive and well-documented.
The following Web site may be helpful to those of you who are not familiar with it: http://toto44.chez-alice.fr/
It is in French, but if you right-click somewhere in the page, you have the option of having it translated (and I use that term very loosely!)
Siegmar Geiselberger also has a very interesting article that includes variations of the PV label in his PK 2005-2 ("Zur Produktion von Pressglasern aus Opalin-Glas in den Glaswerken Vallerythal & Portieux von 1915 bis 2005 Fur die Sammler ein Traum oder ein Albtraum?")
Gerard Triboulot's Web site (in French) may also be helpful: http://www.la-verrerie-de-portieux.com/
Dear Me! I do rattle on! Sorry if I have repeated information that has gone round before.
Shirley in Charleston, WVhttp://www.HenOnNest.com
(please note new Web site. The old Gransplace Web site will be taken down at the end of the year)