When the 1924 patent expired in 1941, they dropped that number from the labels and used only the later patent issued to them.The phrase A PARKER TRADING GAME was added to the box tops in 1937.Almost immediately, very early in 1936, this new patent was added to the Magie patent on all Monopoly games, replacing the single Magie patent.These patents also appeared on the several new varieties introduced by Parker Brothers throughout 1936.
It was produced in limited numbers for only a few months in mid-1935.
Parker Brothers applied for their own patent and the next group of their games stated PATENT PENDING or PATENT APPLIED FOR. This statement was used for a while in 1935, but they discovered that there were other games very much like Monopoly already with patents.
To protect their investment in Darrow's Monoply game, they decided to purchase the 1924 patent to the Landlords game and added that patent to their Monopoly games. In the meantime, PB applied for their own patent on Monopoly.
As far as I know, less than a dozen of these game boxes exist today.
(VIEW HERE) On Dec 31, 1935, Parker Brothers was issued a patent for Monopoly, patent 2,026,082.