I just went through this situation yesterday when I went to the brake shop to have my '69 rotors turned, but they where to thin to turn, so I went to NAPA to find a good replacement and they only had the single piece rotor vs. the two piece, when we compared it with my original rotor it was dimensionally identical and would have worked fine, but I want to keep everything as original as possible without sacrificing safety and ultimately ordered the two piece unites from HBC, when it comes to judging, safety trumps originality and if you decide to mate a original hub with a new rotor may require balancing, doesn't seem worth the effort IMP.