In Australia there are really no papereweight production companies. Some individuals have produced lots - but most stopped instantly when the flood of cheap, but good quality, Chinese weights hits at about a quarter of the price. To try to compete would have been commercial suicide.
Most paperweights are signed here - BUT they often just have initials - given the smaller size of pwts[By the way I have about 65 artists identified for sure as Australian Pwts]. That leads to tricky situations - for instance Eg & GS come from the same studio. Eg = Eileen Gordon part-owner and GS = Gordon Studios blown by whoever, Eileen, Grant or some other worker currently at the studio. A Similar situation occors with SO & OM - where SO = Setsuoko Ogishi, the owner, and OM = Ogishi Mizuno the studio brand. Also because they are not all common for many workers the signatures can be quite unreadable - I currently have around 15 weights with a signature but I can't figure out who the artist was.
My experience is that most Scandinavien weights are well marked. Most USA weights are well marked - often around the edge of the base rather than on it. Canadian seem to be marked ok. Many Scottish weights are well marked but then again many are not and we need the Kevin's of this life to help we strugglers. English are erratic but mot of the ones I have seen are marked OK. The rest you need to be expert in to be at all certain. I currently have c. 90 overseas paperweights by some 55 designers/companies
The above represents my personal experience and I concur with most of what was stated above unreservedly. I guess the trick is to realise that some areas who make lots of weights do not mark them - eg. Murano, China, India & Bohemia are rare to have any sort of marking, whereas Australia, Scotland, USA, etc. are usually marked.