McCall's 6786; ©1963; Misses' Blouse Set "Easy To Sew". Back buttoned, sleeveless overblouse in three versions. Blouse may have vertical darts, French darts or curved seaming at front, curved seaming or vertical darts at back. Curved seams at front have vents at lower edge. Neckline may be high or low.
Links to reviews/blog posts Edit
-  GoofingOff B 31"
[insert your photos of this pattern made up]