they are what I CALL roll welded,put in a machine
and welded with electric current.you have to cut the metal
outer wheel well off,leave the flat of the outer well on
there,take a grinder carefully grind the flat flange away.
hint when the metal gets thin and turns blue STOP, use a pair of
plier's and wiggle the thin metal loose,use a 3 or 4 inch pad grinder
to finish,go slow not to make the inner flange thin.