I used a short AN3 bolt and fed it tthrough the tie-down bracket after the spacers were taped securely in place. I made sure the tie-down was square and then I clamped the tie-down to the spar at both ends of the tie-down with wood to protect the spar.
I drilled all of the holes with a #12, clecoing all the way until I was completed. The drilled out holes for the spacers match the reference lines quite nicely.
I repeated the steps for the right spar tie-down. Tomorrow, I will complete the countersinking for the nutpates, installl the the nutplates and then the parts will get a final debur , cleaning and then primed for final assembly.