I never learned to smock, but that has not stopped me from picking up books on it. "Diane Durand SMOCKING Technique, Projects and Designs", Dover Press, 1979. Some of the photos show inserts, a band of smocking inserted horizontally or vertically. There are no dress patterns in this, just smocking. In "Instructions", it says to "cut the fabric to be smocked, allowing 2 1/2" to 3 1/2" of fabric for every inch of smocking." This is one of the few books I saw that did not tout the expensive pleaters. I need someone to hold my hand as I learn something like smocking and have yet to find someone teaching it close to me. In looking at Caroleen's post, that looks like a simple yoke with the smocking attached, falling into soft gathers below. From the looks of it, I'd say she made up her own pattern for the jumper. Pinafore would be another name for Caroleen's dress.
I don't know what your library system is like there, but here I would be looking into what they have by Martha Pullen. Her magazine "Sew Beautiful", always has a pull-out insert of patterns. Try Martha Pullen's website to ask for a pattern source from the people who post there. I have seen some of these smocked pinafores in older Vogue patterns. A search for "smocked pinafore pattern" at Amazon.com would be one of my first stops.