The KB label ...
From leads posted in the GMB, I checked with Molta Bella Glass at Trocadero.com and they kindly put me in touch with eBay member pwezgma (Robin) who has given permission for the following information to be posted here:
Hi Kevin,me again.I checked my records and KB did go out of business in 1977.They were exporters of good Murano glass and yes the label can be found on other pieces but mostly Toso.
So, it seems that the paperweights with the KB label are most likely Toso and and date to 1977 at the latest.
Robin also finished her message with some additional info on Balboa, which could be useful to some folk ...
Also just as a little info,if you ever see a green Balboa label on a piece,be advised that the Balboa family used to import Barovier and Barbini into the states.The old man of the family is still alive and lives in New York.He still goes to Italy to visit his old glass blowing friends.Some people think that Balboa was a glass blower,not so just an importer.Good luck Robin
[I have posted a copy of this message to the Murano board]