Hacking seconds on late 1970's Oyster Perpetual Date?

[jmcclean40]

I am new to the forum and to Rolex ownership, as I have recently received a beautiful vintage Oyster Perpetual Date Model 1500 (stainless, black dial, engine-turned bezel) as a gift. It has a serial number in the 5 millions, which I believe puts its production in the late 1970s.

Here is my question: Does this particular model have hacking seconds? When I unscrew the crown to set the time the seconds continue to run, so I want to find out if (a) it doesn't have hacking seconds or (b) my hacking mechanism is broken.

Thanks in advance!