After 4 tries I finally got my old 85 380SE to pass state inspection. Thank you all for your posts and advice. Here's what I did...

2nd try - replaced the spark plugs, spark plug wires, and rotor cap. Changed the oil. Most readings improved but not enough to pass.

3rd try - added a bottle of high octane injector cleaner to 12 gallons of premium 93 octane gas. Cleaned the air breather and tubes to the gas recyle flow on the air pump and valve cover. Inflated the rear tires to 45 PSI (spooky step, i thought those old tires would blow up in my face). The readings improved some more and it almost passed. Still failed the low speed NOx test by 25% too high.

4th try - I figured the mixture was too lean so I adjusted the air intake to rich it up a bit and blocked the vacuum advance tube so the engine timing would not advance. I drove it 3 miles at 55mph in 3rd gear and got it tested HOT. It passed with about 5% to spare on NOx and 10% on the HC tolerance.

I guess my tired old catalytic coverter still had enough stuff to bring the NOx down to tolerable levels.