Japanese clothing

I've started making my clothes for Bicolline this summer.

I *know* that on extant paintings of the time, the majority of hats are the typical Chinese pointy hats... but I don't like the fact that they're so strongly associated with Chinese now... I've found better, if less period. For 3,50 a hat, I decided it would be good enough for now.

And, this is the fabric all cut out, with all the edges properly finished (the three on the left are linen, I don't want them to fray!). I had to cheat on the two left pieces and split the collar in the middle. I didn't have enough fabric.

I've started sewing, and hit a snag... the collar seam line, as it continues into the front body piece, and the sewing line for the overlap panel.

Both Saionji and Kass say to sew the overlap to the edge of the front panel, and the diagram in Dalby seems to agree.

But Marshal (I know, modern) tells us to sew the overlap to the collar sewing line, like this:

Trouble is, when I look at pictures of extant kosode in Momoyama: The Golden Age and Japanese Costume and Textile Arts, I think he might actually be right! The okumi sewing line seems to go right into the collar sewing line...

What shall I do?

Add-on: I asked the question on SCA-JML list and I'm not sure I can explain clearly... Here's another diagram...

A: The overlap (in red) is sewn right to the edge of the main body piece.

B: The overlap (in red) is offset from the edge and lines up with the collar sewing line (dotted line). This is the version I think I'm seeing on extant pieces.

Edit: I've looked at a lot of extant examples and, while a good number of them seem to be offset, a lot seem not to be. So, since not offsetting is simpler, this is what I'm going to do! Check out the extant pieces on this page http://www.wodefordhall.com/kosode.htm.