Not exactly this one (the waistcoat will be cut differently), but mostly yes.
I prepared the shirt for the fitting - I assabled only the right sleeve as you can see:-)
After the fitting, the pattern is something like this. I had to add the armpit gores for comfortable wearing.
I started with the neckline slit. I sewed two strips on along the cut.
I made the cut a little longer and made two cuts to the last stitches os the seams. I folded the strips around the edges, tucked the little triangles under and sewed them on the place.
I folded the rest of the strips around, basted and attached them by hand.
I ripped the basting out and ironed.
