CZ! I Polish the track that the foot of the disconnector drags on. The idea is not to remove metal just make it smooth. Notice the tooling marks I leave in the work. It is in front of the mainspring passage. Also polish the inside of the frame where the trigger bar contacts just above and running horizontal just above the trigger bar spring.
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That looks like way more sophisticated work than I do to 150 year old Colts. Guys like you, CM and Alan are like artists, I see myself as more of a blacksmith.