There is a small machine used to make decorative cloth cord which can
also cover new electrical cord with woven material.  Mike Kitner uses
one in his restoration work, as do a few others.  It's a neat little
device which one occasionally sees in operation at steam rallies and
the like.

Another trick is to use shoe lace material.  The flat type of cotton
lace is actually tubular and you can slip a new cord inside for that
antique look.

Philip Jamison
West Chester, PA