I cut a stock oil cooler apart and welded the holes shut. Then cut the bottom off and tapped the holes in the block.
This is one of the projects I wanted to work on making some variations for but there just isn't enough interest to justify me putting off other work to get it completed.
Keating makes a plate but it only has one hole for the oil supply with an external oil pump. At least it was the last time I talked to him.