FWIW
I had a recent issue with a new set of EDM lifters being oversize. In my discussion with the tech at that company, he said they were johnson lifters and they bought them, dissasembled them for the EDM process, then reassembled and packaged. He also said that Comp and some other major brands are all Johnson lifters. I told him that I had a 10 yr. old set of Comps that were more in spec. He said they could be a different manufacturer and listed several. None of them Comp Cams.!!