I didn’t get too many photos of the oval window because it was in a tight stairway. Since the jamb extension was installed from the manufacturer, I tacked a piece of MDF over it and used a flush trim bit with bearing to rout the inside out. Before removing it i made some witness marks to help with aligning the trim later. Then I could use a 3/16″ cut setup on my rabbet bit to rout the setback similar to the eyebrow window. Flip it over and use the flush bit to finish. Then like before set the scribe to the thickness of the casing and score the outside line. After cutting I used a portable oscillating drum sander to true all the curves up. Beading this trim would have required a bent lamination or a CNC router.