Hi Bob ,thanks, it is a nice older super Chuck ,the raised bur is above the taper surface about 1/2 way into taper. Was hopping to find a jt3 taper reamer to knock down the bur can't seem to find one.
Was thinking about a 1/2" - dowel chucked in super Chuck and dowell chucked in lathe 5c collet , and a tool post grinder with stone set to just touch bur to knock it flush with taper . Seems to just be one small bur all the way around ,rest of taper looks good.