well depending on how big you made it, surely you could acquire or make a big sound hole cover with a highly decorative design carved into it.
What??? This isn't a porn site.....lol
drop a homemade resonator in it and fill the whole thing......Voila, Lemonade!
some of my boxes come with thin wood inserts, glue a pair over the edges of the hole to make it smaller, decorated to look in style with the box
i.e. if its rat style, make them look like old planks trying to nail it closed against a zombie, gold spray paint to make a classy framed look, stain to match the fret board and contrast with the box, make them look like 6 panel antique doors in miniature, make it look like a bio-hazard or electric shock hazard sign centered across the hole letting a little on either side open for sound, let your imagination go wild...
Too Much Hole HAHAHAHAHA Make a donut out of thin ply or whatever your top is made from glue it over the hole if possible glue it to the inside.
Drain covers come in an assortment of sizes?
Thought I was reading Kurt Cobain's headstone for a minute