I've ran an Oberg model 600 for years on the VW. Went to what they called a fine mesh screen early on. The 600 used about a 6" diameter stainless screen.
Wanted an Oberg for the GT40. Found out that the Racor division of Parker had bought Oberg. I finally ended up finding getting one from the local truck parts store. About $135 of $145 if I remember correctly. Don't remember the PN offhand, but it is the old Oberg model 600 with Racor's name on it. The fine screen is about 28 micron according to the factory. I always get the bypass warning light kit along with the filter. Had a cam go flat on the VW in first 5 minutes of running on a new engine. The bypass light went on. I ignored it for 5 minutes till cast iron plugged up the
oil holes and the engine started to seize. Duh. Costly lesson not to ignore the bypass light...ever.
You can examine the screen at each
oil change for bits of whatever. Makes it easy to see if something is wearing and releasing metal particles in the
oil.