Did you grow the gourds yourself? And what did you use to cut the one open? NIce work!
I have grown gourd (I actually have a crop almost ready to harvest) but did not grow any of the gourds I used for these ornaments.
To open the gourd I use a very small blade jigsaw. You could probably use a hobby saw (but I never get very get very clean cut with those- I love my power tools)