Follow up ---- after drilling a small 1/8 hole in the breather disc---just left of the flapper---the gobbling, chirping and hooting finally disappeared. Used a slide hammer to remove the disc, which came out w/o any fuss-no heat required. 

I'll be monitoring how much---if any--more oil is vented as a result of drilling the hole.

Suffice to say, I'm pleased the annoying gobble at idle and hoot when the engine shut off---are finally gone. 

Removing my starter cover, and and opening the breather system, I find my valve stuck in this position.  Preceded by increased oil consumption. HA!  That won’t work. Replaced with reed valve. 

Good job !