Hi , They look to be as you guessed early 20th c ,at best late 19thc , they could also be later in the 20thc , the wear does look a little contrived with many of the scratches appearing to travel in the same direction , possible indicating a little assistance in the wears creation ,country of origin could be many , England, France, Belgium ,would all be possabilities ,as you say a good size for the glugging of wine and a set of 8 too ,although to me I would not put them into my old glass time frame , but could still be 100 yrs or so old ,or considerably later !! sorry not to have been a great help .
cheers ,
Peter.