Finally. I'm at a point where I'm very satisfied with the cowl fit.
The pictures below have clear mailing tape to hold the halves into position; there will be a slight gap between the halves once the hinge is installed.
Releasing the pressure from the tape holding the lower rear of the cowl halves worked wonders. The distortion between cowl halves didn't disappear 100%, but is now less than 1/32", which requires almost no pressure to put in alignment with the other half. I marked new index marks at the back lower edge where the cowl meets the fuselage so that when I go to drill the hinge mounting rivet holes I will be able to get back to the alignment that worked well.
The blue oval in the first pic below is the oil sump cooler hole that is yet to be cut. Other blue lines are trim notations for me.
With the cowl in the new, hopefully final, alignment, I continued to trim a bit more here and there - about 6-8 on-and-off's of the cowl to file some, check some, etc.
