Susana, i try to show you … i hope it is clear enough
If you can’t see it so good, click on the pictures, then they get huge.
When you make the pictures larger, you can see more.
The first picture you see the spine, it is the silvery piece like a Y with a long lower part.
The second picture shows you the seam from the back of the body.
I make an open belly in this case.
The opening is from down at the hips, right up to the tip of the nose to have good access for the sewing.
The 2 short parts of the Y go inside the head. The crossing is above the seam from body and head.
Take a unbreakable thread and make a knot in the end.
Then stitch from the tip of one short leg right into the seam allowance of the gusset / head part.
Sew it with 1 cm stitches to the seam allowance down to the spot where the other short part goes into the head, and secure it to the other side of the gusset seam. secure the thread, cut the thread.
Then you sew the long leg of the Y on to the back seam.
I do it, 1 stitch one side, then over the spine and take a stitch on the other side and then back again to the first side …. like this / \ / \ / \
I do it in 1 cm steps.
click on the last picture, than you can see the black thread i used, it goes from one side to the other.
Stitch through the covering material, here the silver, into the seam allowance and back up through the covering material.
Susana i hope this new picture helps you :)