Basically the problem is narrowed down to binding on the sear do to side pressure or squeeze. 

Took a few strokes of the file to the sides of the tang assembly where it fits into the action and problem seems to be solved. 

Since I have the original trigger assembly, I was able to measure the tang width. The CPA tang was about .005” wider than the original.

Will see how it goes when the rest of the work is finished.