This egg is was made by covering an egg with a thin layer of pink polymer clay, and before curing, marking the holes to be excavated later with a cookie cutter type tool. This included a 1 cm hole at the very bottom of the egg which would be used to work with the wires. The egg was cured, then a knife used to finish cutting out the holes, and the holes and exterior of the egg sanded (as smooth as ‘mm’ allows time for it, sadly, never smooth enough).
Little hearts (also made with a cookie cutter, thick enough to have an eye pin inserted in the bottom as the stem, were made, i think 20 total. The initials of my grandchildren were stamped into one side of each of the hearts. The hearts on pins were cured. The eye pins were made from a spool of wire, as most needed to be longer than commercial wires. 
The pins were inserted in the holes and the ends brought out the bottom, and gathered together in a small lump of polymer clay (small enough that it could be pushed up into the egg after the wires were securely curedin the clay). After that, wires were wrapped up over the lump of clay, and trimmed to only include a tiny “bend” over the lump. A base, and a cover was fashioned for the egg and cured again. After that, positioning the hearts within the holes was possible.
I had intended to decorate with marker and paint, the outside of the egg, and to put a wash over the embossed letters…. still will happen i hope, and i will post then another picture. This photo was in the blinding sun and the snow…. not that great. haha.