Cab - I have not got the car out to test it after the investigation due to other work on the car. Will report back!
Car is mostly driven in the highlands about 16-1700 feet. Let off imidently the few times it pinged the day it started. Was a hot and dry day, but also the first time I noticed oil consumption. Oil in intake plenum, oil in pcv hose and a pcv valve that would stick open points to the reason for it. We'll soon find out

I’d try running no pcv valve(two breathers)for a while and see what affect that had on the run-on and oil consumption.

I agree. Figure out what the problem is first and then move to the solution. Putting breathers on it will give you a clue what the problem is.

Finally got around to test a little. Tried a different pcv valve and ran the 160 stat again. Drove some 10 to 40 miles trips and oil level stayed exactly the same. No pinging or run-on.
Loaded the car on the trailer and went to a track day. Ran 7-6 1/8 mile runs at 2/3 throttle (street tires). Drove the car 240 miles back home and it consumed 2,5 quarts of oil (did stop and check/refill) on the way. Same scenario: The two plugs getting fed from the rear upper runners were light gray/white and dry.
Did not here any pinging, but didn't try to get it to ping eighter. Maybe run-on and pinging was not present because of the cold thermostat. Still planning to run the 180 stat again. Just wanted to start from scratch as it sat through the first two tanks of gas and had no oil consumption.
Might try a breather instead of the pcv and see.

Don't think this is a problem but the car has low vacuumn and needs the vacuumn pump it has to run power brakes. The brakes works normal. There are one-way valves inline between the pump and the T-pipe at the booster. Same between T-pipe and intake vacuumn port. The valves are mounted in the correct direction.

The very first thing I would have done is ditch the pcv valve to rule that out as the source of the oil.

That being said, 2.5qts in 240 miles seems like a lot to come from there..... but I would still want to rule that out.

Is you pvc baffled under the cover?

Pcv has a baffle but it might be ineffisient. Quite small compaired to those in the stamped covers. I'll rig up a catch can to monitor the oil from the pcv valve.
I happen to know the guy who had this actual engine in his car before he sold it to the person we got the car from. He says the engine had no problems when he had it and sent some photos that shows stamped valve covers in opposite to the current M/T covers. The owner between him and us didn't drive the car much due to the oil consumption problem he said had always been there. Might be a combo of different things an a quite interesting case😃 We'll find out. Just need to dig a little deeper😀