Whoa - The "gob and fork" is your main halyard. Your jib halyard runs from the head of the jib, through a steel block at the mast tang, to the cheek block on the bottom of the mast, through the in-line block on the halyard and then to the cleat on the port side of the mast. The jib halyard is used to tension the whole rig. The Aussie system replaces all that with blocks and line between the head of the jib and the mast tang. A single line then runs down to the cleat. The Aussie system is a nice-to-have, racer thing although the single line makes the jib less likely to hang up during tacks.

A little better way to run the stock system is to use the main halyard cleat (starboard mast cleat) as an additional turning block. Run the halyard to the cheek block, back up to the in-line block, then down around the bottom of the main halyard cleat, back to the in-line block and then down to the jib halyard cleat. Hope that description is clear enough.