Past oil leak

[jrd1990zr1]

Question for you experienced ZR1 folks. When I pulled the injectors, alternator, coil and starter I noticed quite a bit of dryed up oil all over the place. Don't pay attention to the starter area I was starting to clean there. Anyway the area where I have drawn the red arrow to, is this a cover with a gasket? Could this be the source of the past leak? What is under this if it is removable?

I plan to pull the injector housings and replace the oil cooler lines with a set of Jeffvette's and clean up the entire area before I put it together, since I don't see any fresh oil.

Thoughts? Thanks, John