Sweet Ethnic Bib Vest

I adore this precious little bib vest, presumably from a South American country. Yet again, it was a gift from someone sure that I would treasure it as I love and cherish ethnic folk and indigenous clothing. Although I know it is extremely old, there is stitching that appears to be machine made. I'm baffled by this. If anyone recognizes this type of clothing, I will be thrilled to find out more.