Good write up!!!
Since there were very few choices for wheels way back then, I did that in the '60's as well. I used the correct center for the axle and wider rims from some other larger car. I bolted them together for alignment then had them professionally welded, with the welder removing the bolts and welding those holes as well so I could run tubeless tires. I think I figured 1/16" runout was close enough back then