<VV> Oil leak

[James Cuneo]

Turbo on 140 engine.
So, I was a quart down on oil and had no dino oil. So, I added a quart of full synthetic 5-30 knowing I was going to change the oil soon. Within 20 minutes while driving I began to smell burning oil. Coincidence? Changed oil to dino 10-30, still smell.
Upon inspection I see oil dripping slowly from between the cylinder and cylinder head, onto the pushrod tubes of #5 and #3 cylinders, then onto the ex. manifold.
This roughly coincides with where the turbo drain oil enters rocker galley.
Could it be an o-ring behind the pushrod guide has begun to leak? Anyone have this happen before? It is not leaking from the pushrod o-rings or valve covers or top cover or turbo drain plumbing.
I can see no other leaks or routes that leaking oil could take.
Thanks in advance for your help.
Jim C.   707-326-6220
NorCal
65 corsa 140/turbo