Some arm progress

After some helpful discussions on WhiteArmor.Net, I had some better ideas on what needs to be done to the fore arms.  The ATA arms are known to be very wide.  There's a rectangular ridge (mold line) and now I know what needs to be trimmed away...

With that knowledge, I trimmed away the inside of the right arm...

The item on the right has been trimmed down as well as the "returns" still present on the opening of the other part on left.
 

No instructions and still stuck

The lack of any formal instructions is continuing to slow me down.

The forearms continue to make me look and double check at how this should all fit together.

As I research more, I see how other armor kits are documented and how they go together.

Sigh.

So, my problem is that I cut and trimmed the arms out of the molding lines.  Those cut lines are exactly straight.  However, I am not entirely sure how much I should be cutting away.  To fit, I would assume.  As I align the arms side to side, part of me just wants to make those cuts straight.

Then I look at the ends and look at the end the wrist will be on.  I'm not sure that looks right.

Then I look at the other end...and it seems as though once I adjust one end, the other is off.

This gets fun when?

I'm just wondering about the flat spot...how "big" should that be across?