Here's my version:
Use the largest heart nestie and a scalloped circle to fit the top, cut off one part of the heart like this.
I would run these through a cuttlebug folder to emboss at this point, but didn't for these pics.
Glue in the green scallop. You could cut it in half if you want. That is what we did with the SU! one. I added a little red glue tape along the edge to hole it shut.