A quick update. I removed my manifold today and took some pictures. It appears that the inner orifice is missing in some places, making it unable to fit a 5/64 bit drive in, but still a bigger space than if it were a complete ring, if that makes sense..
The inside of the air intake, which I had cleaned out 2 weeks ago, is completely covered in oil. When I took the intake off, the gaskets had a lot of oil on them and inside where the gasket would normally seal. Oil was on head of the engine where the gaskets came off.