Car passed CA smog test by the numbers but failed the visual. After idling for 1

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Car passed CA smog test by the numbers but failed the visual. After idling for 15 mins they snap revved it 3 times. Puff of blue smoke on 1st 2 revs then cleared up. Has only started to puff a little smoke after idle in about the last 3 months. Have owned it for the last 2 years (40,000 miles). Developed an intermittent miss a few months ago. Check Engine light came on. Checked with diagnostic tool and it identified problem cylinder. Checked plug leads with Ohms meter and that cylinder had bad lead. Replaced all leads and plugs. Check engine light went off, missing stopped and car seemed to run better than it ever had. When I checked compression all cylinders OK except one @ 60% of average but it was not the same cylinder as the one that had the bad lead and which had caused the check engine light to come on. When I did wet compression test (a little oil down spark plug hole) compression increased to about 80% of average. Worn Bore/rings? Worn valve/valve-seat? Worn Valve stem, seal, guide? Car still seems to run smooth and strong. Uses about a quart oil every 2,000 miles. Would a product like Rislone Ring Seal Smoke Repair, Bars Leak Professional Valve Seal Oil Consumption Repair, or the Restore product, or something else be worth trying to see if it can pass smog and get a couple more years before throw away or repair? What do you think: 1. Is the most likely cause of the problem? 2. Has somebody had any luck with one of the above products or something else that might temporarily stop the puffs of blue smoke after lingthy idle so I can get it to pass smog? THANKS for the input!