I've seen a few at auctions over the years. I just remember they went for big money, so they are a thing to collectors. Of course all of the ones I saw were over 50 years old, and this was 30 years ago. In truth the details of them were not the perfection you see on a real keyboard. Most of their keyboards sported painted toothpicks. It looked like they used approx the same area of each single toothpick, to make one key, as size was kinda consistent, and most of the flat ones are tapered. All paint was a higher looking gloss, as were the cases. Most were of the grand piano style, but a few of the box type pianos were sold as well.
Never tried to make one, and didn't really have much interest, due to the prices, so I just kinda noted them. but the keys stood out because of the taper, they were irregular, just the tiniest bit. I think instead of the toothpicks, I would rip some really skinny stock on the bandsaw, make them consistent, and the looks would improve a lot. Or maybe it was because of the irregularity is why they were of value? If so kinda strange. They did call them "Americana" but then at an auction, everything that didn't have a real name was Americana
Not sure if anything good will be
found in a search here, but it's the subject, sometimes all you hear are crickets doing a search