Putting a 318 together and something seems wrong here (see pic)

I'm putting my 318 back together, had it apart due to a bad crank which also wrecked 3 pistons, a rod and a cylinder. Had the cylinder sleeved, replaced the bad pistons and rod, all cylinders honed and all new rings. This is the first time that I am putting an engine together, and I have a friend helping me who is a mechanic.

Anyway, we put the cam in and went to put the cover on but noticed something that we did not really notice when we took the engine apart. See the picture. This just doesn't look right- there are four threaded holes, only 3 bolts and that plate that sits on top looks like someone just bent it to fit that way (it has a hook that fits into the empty bolt hole). This is the way it was when we took the engine out; this engine has been rebuilt before.

Tell me what's wrong here and what the part is called that I think needs to be replaced?