That looks like a pretty cool cigar box banjolele project you have going there. Let us know how it turns out. I wonder if the cigar box will muffle the drum very much. I guess we'll see. With an animal hide drum head, I hope you live in a dry place. If not, you can mount an electric light (small wattage) inside the drum to help keep the drum head dry.
I've embedded two of your photos here to give other readers a quick see...
Here's a photo of what's inside the cigar box:
Well, good luck with your banjolele.