Questions about Type I vs Type II Sears

[painter777]

Type I sear vs Type II.

Except for the Grind mark or the Hole found on Type II.
Aren't they exactly the same ?
What is the Grind mark or Hole for ?
Anything to do with the change of the spring ?

Anyone.......

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.