Nice find you have there!
I know just a little about Blue Ribbons, all of it found by researching it after reading your post! They're often associated with the Aristocrat brand - the various backs for both deck brands originated with the American Banknote Company.
These may only barely be vintage. USPC started using the company seals instead of tax stamps in 1965, and they didn't switch from the liquid-activated adhesive stamps to the sticker seals until sometime in the 1980s, I think.
A timeline for you - a history of the Blue Ribbon brand, uncovered by a little poking around the Internet:
1881 - Russell & Morgan Co. is founded in Cincinnati, Ohio, printing (among other things) circus posters.
1894 - After a few name changes, Russell & Morgan became the United States Playing Card Co., better known today as USPC. By this time, they are focused exclusively on printing and selling playing cards.
1905 - Willis W. Russell Card Co. is founded in Milltown, New York.
1908 - American Banknote Company of New York City expands into the playing card business. They're noted for some exquisite engraved designs resembling the intaglio printing found on many currencies of the day.
1912 - W.W. Russell merges with the newly founded Russell Playing Card Company from the same town, doing business under the newer company's name. In that same year, the Aristocrat brand is created by Russell.
1914 - Finding the playing card business less profitable than originally thought, American Banknote sells off its playing card business to Russell PCC. They now own those really nice back designs ABNC created and start using them for their Aristocrat decks.
1916 - While not completely certain, I believe that this is the year that Russell PCC created the Blue Ribbon brand, using more of the ABNC-created designs for the backs. Early printings of the decks are copyrighted 1916 on the tuck box.
1929 - Russell PCC is sold, becoming a division of USPC. The company name is still in use for several years thereafter - a common practice for USPC when acquiring some of the companies they've purchased.
1980s - USPC discontinues the Aristocrat brand. I'm not certain, but it's possible that Blue Ribbon was also dropped in that same era.
2010 - USPC creates a reprinted version of the Aristocrat decks, using dark red and metallic gold inks and a slightly redesigned Ace of Spades.
Assuming all this research is correct, you may have among the last decks of Blue Ribbons printed, likely made within five years or less of the brand being discontinued. What I uncovered seems to dovetail nicely with what Chris Turner knows about them.