And...the JB Weld repair to the oil filter adapter flange on the block:

Flat as can be. Two applications using a steel single edge razor blade. A fresh new blade works well as a squeegee without leaving much at all on the uncorroded surface. Let the first layer set up, scuff (red scotchbrite, maybe a piece that isnt brand new so it isnt too aggressive) that so it has some roughness for the second layer to grab, otherwise the second layer might separate from the first. Then scuff that layer as well for the gasket/sealer to grab it.
Done right there is nothing to sand.

Flat as can be. Two applications using a steel single edge razor blade. A fresh new blade works well as a squeegee without leaving much at all on the uncorroded surface. Let the first layer set up, scuff (red scotchbrite, maybe a piece that isnt brand new so it isnt too aggressive) that so it has some roughness for the second layer to grab, otherwise the second layer might separate from the first. Then scuff that layer as well for the gasket/sealer to grab it.
Done right there is nothing to sand.