The amount of any penalty or assessment which has become final, or
for which a judgment has been entered under Sec. 22.42 or Sec. 22.43, or
any amount agreed upon in a compromise or settlement under Sec. 22.46,
may be collected by administrative offset under 31 U.S.C. 3716, except
that an administrative offset may not be made under this subsection
against a refund of an overpayment of Federal taxes, then or later owing
by the United States to the defendant.