Possible Evidence the Sweetwater blade was ground

In our original article about our theory on how the SWB was made we mentioned that it was possibly ground prior to the flaking. We believe we have found some flat spots or "islands" on the cast as further evidence that the blade was ground prior to it being flaked.

Below are some pictures of the SWB cast. If you look closely at the cast with a magnifying glass you can see some flat places or "islands" on both faces of the blade. These islands are where the flakes did not run entirely across the face of the blade which left these flat spot islands. We have circled these spots on the cast so anyone who has a cast can find them easily as well.

On the top side of the divot(top side in reference to the picture here) you can also see small scars that appear to show where an island was pried out to form the divot.

Is it possible that the blade laying in the ground for 500 years rubbed these flat spots? That is possible, but if so, why didn't the entire blade rub flat?

This is the same method(ground then flaked) we used to make our SWB replica which has an average thickness of .22 inches compared to the cast  which has an average of .17 inches. Below is a side view picture of our replica next to the cast.

For reference, we will call the side WITHOUT the divot as Side 1, which is the top picture. On side 1 we have circled 3 spots where the flat spot islands are located.

Below is Side 2 which is the side the divot is on, the divot is actually circled and is the middle circle or the second from the left. So Side 2 has two flat spot islands on it which are also circled.

 Below is the picture I mentioned above comparing the SWB replica to the SWB cast.