I don't have any pics, but the job you did on your 177's looks nearly identical to what I did on my now
defunct 170's. I filed a radius similar to what you did (about 1mm radius) and finished off by polishing.
The crack looks like it's propagated about 1/3 thru the arm. It's released enough stress that the two
sides of the fracture are no longer even (in plane).

Hopefully the new Chorus replacement won't have the same destiny.