I recently helped a neighbor revive his '72 220, which had been parked for 18 years.
Assuming your 230 is similar, the breather fitting on the manifold should have a tube connecting to a nipple, on the air boot at the carb throat.
The black plastic vent line from the front of the engine connects, with a clamped rubber hose piece, to a matching plastic line under the battery tray.
The aux radiator fan only comes on with AC or high engine temperature (above 220 degrees, I think).
A certain amount of exhaust from the breather/oil cap (called BLOWBY) is normal and to be expected on a 28 year old car. Thats why cars have breathers and PCV systems.
It might be time for a valve adjustment, then recheck the compression. I don't think your readings are that bad. I'd worry about getting all the stale gas out of the fuel system.
Reccommend you replace all the brake hoses and fluid. Check the calipers for sticking.
Check the rubber 'isolator', connecting the carb to the manifold, for cracks.
Other things I had to do on the 220 included new waterpump (a REAL PAIN on the 4 cyl. with the AC in the way!) and alternator.
Replaced the collapsed motor mounts. The 4 cyl. engines feel especially rough when these
go bad. Hope this helps.

Happy Motoring, Mark

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DrDKW