TJ has Low Oil pressure.... How do I get it back????

Hi guys,

I've got some problems...... I need help/advice.

My TJ has been running really low oil pressure for the last couple of months. It all started after I sank er a while back. Although I didn't hydrolock it, I ended up taking in some bog water through the leaking rear main seal.

Since then I have:

Replaced the Rear Main Seal,
Replaced the Oil Pressure Sending Unit,
Ran STP Engine flush through her twice,
Changed the Oil 3 times (over the last 6k miles) currently using 5w30,
Put that fangled Duralube in first and later that shit they use in airplanes that was on the infomercials for your car (name escapes me),
Checked the Main and Rod Bearings for end play etc (all OK),

All of this to no avail.....

Currently, after a cold start the Oil Pressure sits at the 1/2 mark (Forgive me for my laymans terminology as my gauges are in BAR (Metric) rather than PSI), as it warms up it sits at the 1/4 mark. Regardless of wether im driving in town or doing 75 mph it never goes over the 1/4 to 1/3 mark.

Before this all happened, my Pressure used to be at the 3/4 mark when cold, and usually at the 1/2 mark during normal driving, and just over 1/2 during Hwy driving.

Also, I seem to have a bit more Valve Train Tick than before, and she also knocks a bit while i'm maintaining speed on the road (ie. sounds fine during acceleration and deceleration). I also get the "Check Gauges" light when I return to an idle at a Stoplight right after i've been on the Freeway; thing is when I stop the Gauge sits at the 1/8 mark and suddenly drops right off to nothing.

So WTF should I do with it??? Anyone have any suggestions??? i'm wondering if this thing can be salvaged, or should I start looking for a rebuilder???

The only thing I can think of that I havn't replaced is my Oil Pump.... Is this the most likely source of the problem???

Thanks

Scotty