I don’t know if anyone in our audience is “into” scale modeling, but Karaya (Poland) has resin kits of the N3N, #72005 is on wheels and #72006 is on floats. Don’t know when I will get around to building them, but I ordered both today:
Joe’s Models (www.joesmodels.com) has the wheels version in stock. He is fresh out of the float version (yep, I got the last one!) but I’m sure he can quote a delivery. If not, there is one on eBay right now, just costs a bit more as the seller overseas.