Main bearing question

I seem to have an oil pressure problem after getting the engine to operating temperature. I've done a little reading and things point to worn bearings... main, rod and cam. I thought I'd pull my pan and take a look. I have no idea how the engine was taken care of before I got it, but the pan had a 1/2 inch of sludge in it, even after I cleaned it a few months ago...so that concerns me. The main bearing is pretty worn for sure. Does anyone see that this crank will need turned at all or can I save it?View attachment 1715044763 View attachment 1715044764View attachment 1715044765
I would pull the crank and inspect it. Also, from your photo the oil hole for the main bearing is in the bearing cap. Not sure what brand main bearings you have but oil hole should be in the block. 65'