Oou, those are turned buttonholes. That's a little bit like how I made the curves on my jacket cutaway. I think that would make a very, very good buttonhole for the strap and encase all the lining and canvas etc.

I think the stitch I was talking about may actually be called a buttonhole stitch. I've seen it used in larger form to finnish a raw edge of a hem, but on the buttonhole, it is very tiny.

Still look forward to Barb and the Wizard's opinion.