From what I gather from various Chinese websites, the first generation Man Shing was decommissioned in 1969 and I suspect the one we see above was the next generation that was commissioned in the following year. However, I could be wrong - perhaps there was another generation of ferry after the 1970 one? Man Shing did do the trip from Central to Ping Chau at one point, but the one above was one of the HYF ferries plying the route between North Point and Kowloon City.
Man Shing was one of three boats owned by HYF - all with a 'Man' name. They were sold in 1998 and two are rumoured to be still plying their trade in Thailand.
Anyway, I am pretty sure someone out there (nudge nudge, wink wink gweilo8888) can be more specific about the history so in the meantime I can mention that the background in these shots is once again North Point. You can see both ferry piers in the background as well as the old North Point Estate (the lower buildings closer to the shoreline).