If you zoom in on the pic of the hard drive, it looks like the pin got pushed in instead of broken off. You can see the pyramid shape of the end. Might be able to take the board off and push it back into place. Other than that, it looks like a typical ide drive, seagate maybe? Likely candiate for a replacement would be a CF to ide adapter, but you'd have to pick the CF card size to match what the computer's bios will accept.
-edit-
Looks like somebody tried to force a keyed connector on backwards. I'll bet the connector has a plug on pin 20 that is supposed to fit in the hole on the upper (pic orientation) row of pins, and instead pushed the pin in on the bottom row.