Stan:
Taper pins are pretty neat. Good for locational fits. I think you'd have to drill & taper ream both together, hub and arm, for good enough alignment to assemble. I've drilled/tapped the large end and built a simple puller to get them out of my lathe.
I see you've done this already. But, could you have blind drilled both the arms and hub. Oversize ream (.126") all then trap a pin (.125") between the parts of they can't escape. Might have worked but I'm late to the rodeo.
Nice work, thanks.
Hugh