I just re-read one of Jamey's early posts about the Boshan industry.
Boshan is in Shandong province, which during the early part of the 20th century was a German "protectorate." Hence Tsingtao beer. But they also established glass factories to do European-style glasswork.

1937 is the date Japan invaded and occupied. Jamey stated that the Boshan glassworks were diverted to make beads in the Japanese style, only cheaper.

So 1937-1945 seems a likely date for these Boshan beads.

LATER, back from a Wikipedia trawl:

As a consequence of the First World War, Germany lost Qingdao and its sphere of influence in Shandong. The Treaty of Versailles transferred the German concessions in Shandong to Japan instead of restoring Chinese sovereignty over the area. Popular dissatisfaction with this outcome of the Treaty of Versailles (Shandong Problem) led to the May Fourth Movement. Finally, Shandong reverted to Chinese control in 1922 after mediation by the United States during the Washington Naval Conference. Weihai followed in 1930.

The return of control over Shandong fell into the Warlord era of the Republic of China. Shandong was handed over to the Zhili clique of warlords, but after the Second Zhili-Fengtian War of 1924, the Manchuria-based Fengtian clique took over. In April 1925, the Fengtian clique installed the warlord Zhang Zongchang, nicknamed the "Dogmeat General", as military governor of Shandong Province. Time dubbed him China's "basest warlord".[7] He ruled over the province until 1928, when he was ousted in the wake of the Northern Expedition. He was succeeded by Han Fuju, who was loyal to the warlord Feng Yuxiang but later switched his allegiance to the Nanjing government headed by Chiang Kai-Shek. Han Fuju also ousted the warlord Liu Zhennian, nicknamed the "King of Shandong East", who ruled eastern Shandong Province, hence unifying the province under his rule.

In 1937 Japan began its invasion of China proper in the Second Sino-Japanese War, which would eventually become part of the Pacific theatre of the Second World War. Han Fuju was made Deputy Commander in Chief of the 5th War Area and put in charge defending the lower Yellow River valley. However, he abandoned his base in Jinan when the Japanese crossed the Yellow River. He was executed for not following orders shortly thereafter.