hey jim. have you thought about offering a semi finshed adaptor, one that just has a 1" bore for the hub and we can bore to the size we need. that way you could have a ready supply on hand for those able to finish it themselves.
It has always amazed me what customers do. Instead of calling the manufacture and finding out why they have problems they will either destroy the part and wonder why it doesn't work right or post some *****y thread about how the part didn't work. Lucky it was only the former in this case.