If it isnt knocking,run it
Agreeing with @kmccune now it is not the best of situations, but recall a few vehicles at work that lived on for years with that condition, engine is shot, but keep up with the oil changes and 2 or 3 years bigger factors will probably make the vehicle fiscally unfeasable.
OK, It’s time for another one of my long shots. You say the oil pressure dropped suddenly. Bearings don’t go at the snap of a finger. This may seem too obvious but have you tried a new oil filter? I’m wondering if the element might have collapsed due to a defect and partially restricted it’s output. Overly simplistic I know but it’s quick and easy try if you haven’t already done it.
Here’s something interesting.
One of things to check when inspecting the timing chain is, check the splines on the crankshaft gear to see if the splines on the gear for the oil pump drive are in tact.
Tester
As a matter of fact, a former colleague of did run into a situation where the oil filter he just installed WAS the problem, as far as low oil pressure was concerned
By the time he figured it out, however, it was too late, and the damage was done