I think the front mark is a machine witness mark but the dimple is still the dimple.
You can easily compare the sight to the pictures in your post and compare.
The old is a single angle front and back, like a triangle.
The new is a steeper angle to the top of the slide and then a shallower angle. I think it's easier to see for real than it is in the pictures.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."