Never heard of this one before but I have a constant very slight leak of oil from my head gaskette on an L20B Carb engine. The leak is just between (and below) the #2 and #3 spark plugs at the head gaskette, NOT the pan gaskette. There appears to be no oil in the coolant, no coolant in the oil, no cylinder pressure loss, no loss of power, no running problems of any kind associated with this leak, just a constant slow seeping that leaves occasional drips on the driveway concrete (my wife is not so very happy with this).

I'm considering doing a head gaskette job but thought I'd check here first. I also thought I'd just re-torque the head bolts and see what happens.

Whaddaya think?

Welcome to NICO!

The head gasket bolts are probably torqued just fine. Its rare that they would back out. However, it wouldn't be tough to pull the valve cover, set the torque wrench and find out.
More likely is that the gasket is just deteriorating around the plug wells. Its an easy enough fix on a that car if you decide to do the whole job.