300sd rolled bearing (I think)

[Biotour]

Well let me start off by giving a brief history of the car. I bought it about 3 months ago and it was running fine, I didn't notice any major oil leaks and was able to drive it around with no problems. Then I decided to do a valve job to improve performance, and inadvertently introduced air into the fuel lines. I thought I had made the valves too loose so I tightened them back up and realized it was just air. Oops. Well I went for a 400 mile drive and ended up not tightening the valve cover enough so it leaked some oil. I got that fixed but I still had to redo the valve job so I did it when I reached my destination. After the valve job was finally done I started it up, drove about 100 yards, and a loud distinct rod knock appeared. I had topped off the oil before the valve job, and just let the engine idle for about 20 min after which the knock went away. Then I had it happen again a couple weeks later, the dipstick was totally dry. And it was knocking much louder than before. Did an oil change and filter, this time I just drove it around town for about an hour before the knock went away. And I've been checking the oil level every 20 miles or so since. So last weekend I was driving 10 miles back to my house when it started knocking really loud on the freeway. Pulled over, oil level was at the low mark. Pressure was bouncing between .5 and 1 at idle. Drove to a buddy's house really slow who just happened to live nearby. Topped off the oil, let it idle, it sounded much worse and ended up stalling. I haven't started it since. It definitely sounded like grinding metal. I want to pull the pan and check for bearing pieces, is it possible without removing the engine? Is it worth rebuilding or do I look for new engines? Or just another car? I live in long beach ca so if anyone wants to help me out that'd be awesome. It's an 81 300sd, 263k

video here:
http://www.youtube.com/watch?v=G2UXqc3aofM