The pattern is the 1960's reproduction pattern Simplicity 2154, and I even bought a bunch of yardage of linen to make the rest of the suit (which strangely enough, about the same number of total pieces that this blouse).
I love the fabric, which is a sturdy cotton from Lotta Jansdotter's line that I picked up at Z Fabrics. My only two mods to the pattern were extremely minor: 1) I decreased the seam allowance along the hips, and 2) I did the "Mena Test" of Sew Weekly fame and omitted the side zipper.
The top is sleeveless, but it was way too cold/windy to bare arms on the day I took these photos, but they're finished off nicely with some bias binding. The whole thing is pretty simple to sew and I can't get over how nicely the collar lies. Yep, I definitely need at least one more of these!