Slant oil filter canister question.

Bad news, I'm afraid: that looks like the remains of the anti-drainback flap. If you turn the canister upside-down and look at the baseplate holes, you should find pliable rubber inside each one. I'm guessing you'll find nothing but metal and cooked bits of rubber.

You're looking for a new canister. Part № 2128 548 or 2128 876.