Well, you cannot believe everything that you read on-line. I do not have any idea what this is supposed to be, but I really do not think that it would ever function as an oil pan!
So, this is my new one:
It is a little weird, it looks like they ground down the metal on the outside, but not the inside:
I ended up pulling up the YouTube video that I linked while laying under my car trying to figure out where a bracket was so that I could spray the bolts. I guess that it is above the header (?), which I still have not removed, and while I marveled at PB Blaster, those fasteners are on tight! I sprayed them again.
There was some plate inside of my oil pan, I sprayed those bolts, which also looked rusted, and they came off easily. They required one firm twist with my wrench, and then I used my fingers. I wanted to clean out the PB Blaster, but I just want to clean the entire part now, there is burned oil and metal shavings. Magnets wouldn't do any good!