David,
What diameter would a scale prop be? The 19BB will be tons of power for so small a plane so prop selection will be based on the airplane more than the engine. The thing that worries me more is where the CG will be. IIRC the Miss LA has a very long nose and not a very large tail. The weight of the Veco could very easily make the airplane nose heavy to the point the tail may not be adequate to overcome a very far forward CG. Just for fun, check on the CG location now and let us know.
Ted