So I ended up taking my car to my trusted mechanic, in hopes of getting a 2nd opinion on my cars state inspection failure. The Midas quote was 441 dollars to get it "passable". The recommendation was to also install a timing belt, water pump, and seal kit change; 500 dollars more.
So apparently the law states that for my OBD I car, the only requirement is that the catalytic converter needs to APPEAR to be working. It needs to be there physically, but there is no emission test or anything. Even if it's hollow (which I do not believe it is, because I took it off a few months ago), nobody has any way of proving it without removing it all together. What Midas didn't tell me:
The car didn't fail because of the rusty converter, it failed because of a small exhaust leak between the catalytic converter + header pipe flange. I had forgotten to install a gasket in there when I did some exhaust work, a n00b mistake .
So it ends up that in order to get my car in "passable" condition, it cost me 4.49 for a new gasket, and between 20 minutes of my time to crawl under there, unscrew a few bolts, and slide in the gasket.
They were right about the timing belt, though I think that the claims were exaggerated. I had a new timing belt, new cam seal, water pump, and every other accessory belt replaced, for 475 dollars including labor. The mechanic said that the old belt was indeed soaked in an oil bath, and was a little soft, but not about to break.
Avoid chain stores for auto repair!!!