Whats the diameter of the face of the hub that the prop seats against.
You could use that hub,use locktite,then you could also use setscrews as long as the hub slides over the crank past the threads about a 1/2 inch or so.
The first crank i welded is ok but i wouldnt sell it to anybody.And i sure wouldnt charge anybody.Like i said,it was my first crank.Its just a hair off in my lathe but i think it would work.This is not for my BME twin.Its for another project i was trying but i might just drop the project anyway.