Po Hing Theatre (first generation) [c.1904-c.1926]
The Public Works Report for 1905 states:
65. Kowloon Roads.—Two contracts were undertaken out of this vote ; one for lowering the summit of Robinson and Austin Roads, extending the former to the Yaumati Theatre and completing that portion of Gascoigne Road between Robinson Road and Station Street; .......
A building at the junction of (then) Robinson Road and Gascoigne Road (on the eastern part of I.L.1011) is visible already on a 1904 map on hkmaps.hk. This means that the building stood there even before the roads mentioned above were finished, and access was from Kansu Street. On the 1920 map it is labelled "Theatre".
The estimated lifespan therefore is from about 1904 to about 1926.