All the Hercules diesels I have worked on have brass screen type oil filters. From what I've been around them they work very well. This is how I clean them.
I rinse them in the parts washer and brush off the gunk/dirt off the outside with a soft bristled brush
Scrub around inside with the same brush.
Then carefully rinse the inside
After all the dirt is gone from inside, I hold my finger in the hole and fill with washer fluid, to rinse it from the inside out. This pushes the dirt off of the screen from the inside.
Wipe with a clean rag and your ready to reinstall.
There is nothing wrong with the brass filters. I kinda like them myself because I'm cheap! :D
Just a helpful hint to those new to brass filters
Bob
I always liked the brass ones to,I have a aqua-parts washer and toss them in there they come out like new.