According to the 1948 publication Dogs In Britain, A Description of All Native Breeds and Most Foreign Breeds in Britain by Clifford LB Hubbard, the Sleeve Pekingese is a true miniature of the standard-sized dog, and was also known as the Miniature Pekingese.
In Hubbard's time, the term Sleeve was applied in Britain to a miniature Pekingese no more than 6-7 pounds in weight, often appearing to be only about 3-4 pounds.