Hollywood Road and Possession Street

I've been studying the old Hong Kong map as of 1843, 1845, 1856, and 1866 for few days, and I've found that Possession Street seems to have been part of Hollywood Road in the past when there was still Gap Road during my investigation on the maps.

I have a few questions to ask:

Firstly, is it true that Possession Street was part of Hollywood Road in the very beginning? If yes, since when has Possession Street been separated from Hollywood Road?

Secondly, may I ask when Gap Road merged into Hollywood Road?

Looking forward to your answers.