-
I am not super familiar with sewing zippers, but I get the general idea and the different ways to do it. I have been trying to look very closely at how you did your Zipper Grizz and cannot tell. Did you mark where you wanted it to go and then pin it and sew it to the outside and then just cut the fabric slit open in the back? Or did you do it differently?
-
When sewing a zipper down I've always got it open, for maximum flexibility with movement w.r.t. sewing machine. This means marking the fabric with the cut line first, making the cut, and finishing the edges by rolling, or bias tape. and attaching the zipper sides. Don't reckon any finishing the edge is needed for Tyvek though.