My friend and I made something similar since we were like you, looking for them in stores and unable to find them, and her husband got us a roll of rebar tie-wire, and it's easily formed with your fingers and then we stuck them into a pumpkin that was spray painted silver.
The baby cards were made/donated by another lady in our church and that was mainly what she'd made, so we made an entire pumpkin of just baby cards. You can poke the wires in wherever you want them to make your display, as evidenced in the picture, you can put a TON of cards on 1 pumpkin since it's VERY heavy and will hold it's weight. The rebar tie-wire works well because even when it's really long, it doesn't bend under the weight of the card, yet it's easy to form with your fingers. And this time of year pumpkins were such a cheap option! Spraying it silver made it blend into things more instead of having this huge orange ball on the table. Just an idea...but really an idea for craft shows, not for home display as the pumpkin gets gross!
Wire card holder?
