This is what will happen with these cars whenever blowby begins. The drip is most likely from the drainback tube that leads from the oil separator in the air filter to the oil pan. You CAN put an o-ring at the bottom of this tube and it MIGHT help. The oil in the air filter housing is because blowby forces oil through the breather tube at a rate faster than the separator can handle.

Once you determine how much oil the engine is using you will know more. If it is using a lot, like a quart every few hundred miles, the only cure will be liners, rings and you should do a valve job while you have it apart.

The oil pressure being pegged is a good thing and is normal. When the engine is hot, it will probably fall to around 1.5 give or take. As long as it doesn't fall below about .8 bar, you're okay with the bearings, etc.

Good luck,