1988 744T 160K

This project car shows evidence of oil leakage on the passenger's side around the oil cooler lines as well as the area around the aluminum filter adapter and engine block.

I have easy access at this point to remove the large bolt that holds the filter adapter to the block
(1 1/4" box end fits fine). I am assuming there is an O-ring to seal to the block? Perhaps O-rings at the fittings to the oil cooler lines as well? Anyone have insight into what looks like a simple R&R to help stem the flow of oil upon returning this car to life?

I am familiar with the potential leakage problem between the oil return tube and the block. The buildup on the block points to a long term leak between the block and aluminum filter adapter (for lack of a better word).

Randy