Thanks to all for their suggestions. The cable has been removed by snipping the cable tight to the lever body, inserting a thin box nail (my smallest pin punch was a bit too large) and tapping it out from the rear. The box nail point was blunted to prevent it from driving into the lead cable end and swaging it in the more firmly.
Once again, Dale's Classic Rendezvous list has proven to be an amazing resource for the care of vintage lightweights. Such a large number of wrenching tips shared by listmembers over the years (and maintained in the archives) has been of inestimable value to me.
Charlie Young
Honey Brook, Pennsylvania USA
Andrew suggested:
> Charlie- The best way I've done is to use a prick punch from the underside
> to hammer out the lead end. Some times one can twist the cable and get the
> head to rotate too, like stuck seat posts getting the head to move is much
> of the battle. Avoid drilling at all costs as the differing hardness of
> the head (lead and steel) will make the drill walk all over the place, as
> you have experienced. The screw will only expand the head and further
> wedge it into the lever.