B&B = Brown and Bigelow. A major producer of playing cards in their day.
Quote:
1896 -- Brown & Bigelow, the first company to own the rights to the Hoyle Brand is established.
1927 -- Brown & Bigelow playing cards are introduced. A subsidiary of Brown & Bigelow was established to bring their products to the retail market, Hoyle became such a strong brand name that after 1975 the divisions name was changed to Hoyle Products.
The stamp is an RF27. Catalog value $3 (mint); $0.25 (used).
The stamp was issued in 1940 and was the last design of the Playing Cards Revenue stamps issued. The US tax on playing cards was repealed on June 22, 1965, so that stamp was in use for nearly 25 years.