Maybe this helps… This brand - NRG Innovations
http://www.getnrg.com/ - manufactures many very good quality quick releases.
I'm still thinking about this brand to change the poor quality Traven Technology quick release of my 3 Wheeler....
Their simplest Gen 2.0 looks excellent and you have plenty of choices for the color
http://www.getnrg.com/index.php?route=product/category&path=69_18And they have plenty of hubs, again with different sizes, patterns and colors. But the key one (in my opinion) is their SRK-WDH
http://www.getnrg.com/index.php?route=product/product&path=172&product_id=1854 because it fits direct into a standard steering column with Woodward splines, thightened with a couple of easy allen screws and ready to go. No welding nor other complex stuff.
I don't know if the combo of the Gen 2.0 with this SRK-WDH would work with your Morgan and the horn in the center, but it's a good option to investigate.