Well, I've tried every way I know to save you from a complete rebuild. When you said the crank, rods, and bearings were fine, I cheered thinking you would be okay simply sorting out the valve train. Unfortunately, after seeing these latest pictures, I have to agree with everyone else. This engine is toast. Not just from the burnt bearings, but from the array of mismatched parts. If PE provided this engine, they should be ashamed.
I believe the root cause is the poorly matched valve train components. They were the cause of the earlier poor performance when they were keeping the valves from sealing properly and then when a lifter failed, your
oil pump ate a chunk of metal causing it to seize, shearing the drive shaft and causing your
oil pressure gauge to go to zero. In the future, you have the gauge for this purpose. First you believe it until it is proven wrong. You continued to drive the car with no
oil to the bearings thinking the gauge failed. That finished it off. Lesson learned the hard way, but you never should have been put in this situation. There are a lot of questions for the previous owner and the engine builder.