You might give Roger a call @ "The Wheel Shoppe" www.thewheelshoppe.com
...... He builds probably the nicest Banjo wheel available and has all the knowledge available to maybe do a conversion to your Momo hub. I found this "Wheel Shoppe" Banjo wheel on ebay, the guy only used it 1 month in a T bucket and wanted a smaller wheel (???) And it was even the right color!