Maybe overkill, but getting a long, precise slot for the flat mount rear dropouts from Paragon was testing my align-by-hand skills, so I machined up a little fixture attachment that looks good now. Put it on the reverse side of my seat stay coping fixture, adding a dummy BB vertically oriented and a 4 axis mounted v block to hold the tube. A pic makes it clearer: Attachment 104380. Lets me swap out a couple of parts and leave it all mounted on the Bport.
